Sharon, it will be great if you can join us but I am afraid that I have some bad news on the hotel front.
Hilton is out. Apparently old Conrad just didn't like water or gondolas or something.
Marriott is
almost out. There is no Marriott, per se, in Venice. The closest you can get is
the Ramada in Mestre.
Ramada International is operated by Marriott and according to the website you can use your Marriott Reward points to get a free room but it does not say whether you can earn points by staying there.
Also, if you decide to go with the Ramada, keep in mind that it is in Mestre. Take a look at Post # 8 to see what this means.