I finally gave in and called Marriott's Rewards line. After listening to an automated man speak (admittedly he was able to understand all my responses and problem), I got transferred to a human and told him my problem with the Autograph Venezia billing as the Grand Hotel dei Dogi and as a result not getting the x5 points for the $292 spent on taxes (should be about 1500 points - 292) and here was the response after I told him I'd spoken to Chase MR Premier cards twice:
REP: "Sorry I can't help you with that. I don't have any control over it. You will have to call the hotel."
ME: "In Italy?"
REP: "That's the only way to get them to change the way they billed it."
I hung up. I am going to take all your advice and email Andy. This is ridiculous, especially if it is happening on a larger scale, and especially the idea that I'd have to call Europe to get my points.
PS - You can now be certain I will never stay at this hotel again, free or not.sc