I used my Resy benefit at the Red Window in San Francisco. My bill was 100.39, for which I received the $100 statement credit. Then to my pleasant surprise, I received an Email from Rakuten that I had received 500 points. 500 MR points for a .39 expense isn't bad at all!
I think you actually have to look in the Rakuten app to see which nearby restaurants are in Rakuten dining and then compare that with the list of Resy restaurants. Or, it would be nice if someone with more ambition than I would write a MaxResy website to do the tedious work for the rest of us.