This is actually an interesting question, since Starwood allows you to earn Starpoints when dining at a Starwood hotel (or just having drinks at the bar), without a hotel stay. I do this all the time at the W New York when having drinks in the lobby bar - they just punch in your SPG number and the points appear on your statement, even though I'm not staying at the hotel. This would be a nice perk for Marriott to consider offering as well.