In the 1990 - yes. But nowadays? Tomorrow?
Not so sure about that. First, militarily Russia is far more powerful and it also has the huge advantage of strategic depth: key Russian infrastructures are far away from China whereas key Chinese infrastructures are all very much within Russian reach.
Then China does not have many good neighbors. At the very least it needs to worry about the USA, Taiwan, Japan, Vietnam, and India, plus the DPRK and Pakistan as possible sources of instability. And remember, the Vietnamese beat the crap out of the Chinese in 1979. Big army does not mean good army.
China also have much more severe regional issues.
In contrast, the only likely foreign enemy to Russia is Georgia, assuming they did not learn their lesson in 08.08.08, and separatism if finished in all of Russia.
As for China's size, it is as much a handicap as it is an advantage. The ratio of natural resources per capita is so much higher in Russia that it makes it far more flexible than the huge China.
Right now, the major Chinese "threat" to Russia are illegal immigrants, and that is not much of a threat, I would say.
All in all, I would say that Russia packs far more power, both potential and actual, than China. Finally, none of that matters very much because both sides have nothing to gain and all to loose from any kind of problems. They are in fact wonderfully complimentary to each other and all the signs are that they are in the process of building a very long term strategic partnership....
The Chinese have two options really: to have the Russian bear obliterate their entire society into a stack of smoldering ruins or to have the Russians as their personal pizza delivery boy bringing them their "petrochemical pizza" right at their doorstep. Which do you think that they will choose?
Also, while Russia is growing economically, it becomes a fantastic market for China, in particular in the context of a collapsing USA and Europe. So not only will the Chinese get their energy from Russia, they will also sell their 'Wall-mart goods' to the Russian market which will accept them with gratitude.
Lastly, Russia is also interested in a partnership with China and therefore, should China ever get into a crisis with the USA, Taiwan, India or any other party, Russia will "cover the back" of China.
I think that we are far too influenced by Western history. This is Asia, and both Russia and China have a long history of being very, very, skilled at Asian politics. The very last thing either party will ever do is act like some dumb cowboy and try to invade each other, if only because of the fact that geography makes both of this countries totally un-invadible.
One more thing: look at Kazakhstan - an amazing and often overlooked country with some really amazing people. The Kazakhs are very smartly playing it all very low key while in reality building excellent ties with China and, even more so, Russia. They also want stability above all else, and then good commerce and peace. As far as I am concerned, I have great hopes that Russia, China and Kazakhstan will continue to build a huge territory of stability and trade which will gradually entice more and more smaller nations to join it.
Look at it from the Russia point of view: look at the Balts, with their overtly racist and Russophobic ideology; look at the Pollacks, who dream only of being the first in line to brown-nose the USA; look at the rest of Central Europe - Rumsfeld's "new Europe", which is anti-Russian to the core; what about the EU, which is oh so busy trying to save the EU banking order and dealing with immigration (a lost cause if I have ever seen one); look at the USA, run by AIPAC and Zioconned Wall Street. Why would Russia ever find any of them attractive? Oh sure, they will sell them gas and petroleum, and they will smile at official receptions, and speak of a "community of Europe from the Atlantic to the Urals" when in Paris. But in reality, Russia's future is in Asia, with partners like Kazakhstan, China and India. Countries which have far more to offer and which do not share the sclerotic and maniacal desire of the West to return to yet another Cold War.
I would even say that Russia and China have a long term mission that they, and only they, can truly accomplish - to slowly press the US military out of the Asian-Pacific theater and to replace the US imperial order with a multi-national Asian security system.
Historically, the 'Anglosphere's ZIOCONNED mindset' was formed on two islands: the British Isles and the USA (protected on all sides from invasion). So the Anglos have almost always fought their wars far away from home. Russia and China are land-powers, who know all too well that the enemy can *drive* to their capital city. They are far more acutely aware of how devastating wars can be and they do not have the typically Anglo sense of arrogant impunity. This is why they will not seek to establish an imperial order with one big policeman in charge, but a multi-polar system in which every country's security depends on the security of every other country....