Banning Bitcoin might elevate the price. People will continue selling it on the black market and start smuggling vouchers into the country. People will have to pay premium over the market price. Everybody will forget about China in a couple of months.
A ban on something always makes the price of a product to go up, but I do not think bitcoin is going to forget abut China, if you can sell a few hundred dollars above the market rate you can sure many people are going to want to buy bitcoin in an exchange and then try to sell them to Chinese investors and holders, it is going to be a risky endeavor and something I will never do, but if China banned bitcoin then that scenario is likely.