Do you think that China is controlling/ruling bitcoin yes or no?
First of Bitcoin is decentralized digital currency. So no one control bitcoins.
Second things as Bitcoin can make movement as most of mining farm is china as they are producing more bitcoin then ever in world. But that does not means that China controls bitcoins.
Was a decentralized currency. The mining (or how it has become a monopoly) is now the point of centralization. If China stopped mining collectively (thought exercise, bear with me) the network would be crippled with congestion. That sounds like a form of control to me.