I don't have an answer to this, but this is in fact exactly a question I have been thinking about too before making a reservation lately with a Ritz Carlton - to make sure I can get points / night would count towards Elite etc.

everywhere on the Marriott Rewards website when referring to earning or elite benefits etc, it says "at participating Ritz Carlton locations" (or something like that)...and yet I tried very hard to find a list of these "participating" hotels and couldn't really find it at all. anyone has a clue ?

at first I thought it's just excluding certain obvious ones like Ritz Carlton Chicago (which is in fact a Four Seasons hotel and does not belong to the Ritz Carlton chain). but now it seems this "participating" term might mean more than that...