No, they are not controlling bitcoin, maybe they want to, but they just can't because bitcoin is a decentralized one and no one can ever control it, except maybe if its Satoshi Nakamoto, but let's say that they are on their way on controlling bitcoin, and they are on 65% of the process of controlling it, but the population of bitcoin won't allow this thing to happen, it is possible that there would be War in this virtual world between China and the other countries that is holding bitcoin.

But no worries anyways, because that would never happen, unless they will make a coin that can surpass the superiority of bitcoin amongst of all other coins out there.