During the course of the past year, I've discovered that many service employees actually don't know how to operate their own POS machines, even for local cards. As such, I recommend that anyone who goes to China on a regular basis should spend an hour getting a local account, and connect it to WeChat/Alipay. You shouldn't have issues using your foreign cards at hotels or nice restaurants, but convenience stores and more local restaurants might pose problems. As I mentioned in the WeChat/Alipay thread, ICBC and CMB are the only two banks that I am certain work with passports.