I used a 10% Renaissance offer for my Sapphire Preferred in Shanghai Aug 27 23. I had a heck of a time getting the credit. Probably because it coded, at least on my statement, as SHANG HAI LONG ZHI MEN. I called about 3 times, eventually got a rejection letter. Finally decided to try and send a secure message with photos of my email confirm for the night. It was in CNY, but corresponded to the $100.86 on my statement. One would think they have a spreadsheet or database of the hotels and corresponding companies operating these hotels. Anyway for anyone booking international hotels under these offers, be alert. Crazy thing, a few weeks after I send the photo of my receipt. I get not one, but two credits of $10.09 two days apart. It's an interesting game we play.

I'm pretty sure I've done the double dipping with paypal/credit card before. Can't remember the details as it was quite a while ago, but I think it does work.