Yes, they are a power house, but recent events show that without China bitcoin will move on. to answer your question, bitcoin is very much alive, china or no china.
DOn't worry about CHina, bitcoin is world wide use, CHina market is less than 20 % and it is better now to move out CHina, Now they go to Japan and south korea. It is better because both countries are more open minded than CHina. The Chinese traders will move to both countries I think.
On the contrary, the opposite had happened. The price is going strong without China and I'm seeing a bull run again and maybe push the price to $5000. We don't need to worry about China now because others have taken over like Japan and South Korea in Asia. And the they stay out of the bitcoin picture, the more they become irrelevant to us.
It will be more correct to say that China is dead without us and crypto-currencies. The prohibition of crypto-currency in their country leads China to self-isolation and a decrease in the flow of money into its economy. Sooner or later they will understand it and will themselves want to return to the world market of crypto-currencies. Perhaps this will happen by the end of October.
There are alot of news saying that China's ban is just temporary. If that is true, then we will see them again. The market didn't suffer from them, but the Chinese investor who have lost a lot of opportunity to profit. They have been put at a disadvantage by a particular situation or course of action because of their Government's decision.