It is a fact that mining power is mostly based in china. And there are so many bitcoin adopters there. But i don't think they totally control the bitcoin. They only have enough impact.
Yeah no doubt China is well developed country and there are so many rich people who can make bitcoin high for investing but still they can not control bitcoin because there are 90 percent countries in the world are bitcoin supporters and they are making bitcoin web stronger and only china can take hold over the growth of bitcoin.