This is all I can find. Couldn't find a list.
Where can I redeem my Express Comps?
Look for the “Express Comp Accepted Here” sign at participating restaurants, box offices, and more! Express Comps are not redeemable at retail outlets.
I would just go to the players club at the property and ask them. The may have a list they can give you. I know that MGM had a list. I think it may change from time to time so I would ask to be safe.