I'm a foreigner who spends a lot of time on the Mainland. When I first established my wechat a few years back there was the option to add a VISA/MC card but after adding the card it always said not supported and I deleted the card. I've had a Chinese bank account for a while that's linked up. However in December, I noticed the wallet had changed a bit since last time I checked. The card entry looked a little different and I was able to add a US Visa card. I checked my card account and a small credit $0.05 from WeChat was there.

Since then, I've been able to choose that card as a payment option in limited scenarios. I can't select the VISA when using the pay app (i.e. QR code) or transfer but buying things with JD or Meituan when they bring up the payment selection on WeChat allow me to choose the VISA card for payment. I am guessing it is vendor specific but all the charges are applied to the card as WeChat and not the vendor.