The mechanic seems something like this:
1) Yuan is loosing buying power
2) Chinese buy all BTC that they can pushing up BTC/CNY
3) When BTC/CNY is too high they are buying dollars to buy BTC pushing up also BTC/USD
Now, if you consider this chart from 2016-05-05, both USD/CNY and BTC/USD reached a 70% increase in value (the gap is closed).