Basic room charges and meals charged to the rooms (YMMV if the restaurant is some separate entity from the property) appear to count properly to Ambassador spending

Everything else is inconsistent, such as parking, resort fees, spa, etc. Sometimes it counts, sometimes it doesn't.

Meeting charges (room, equipment, banquet, etc) never seem to count

Doesn't seem to matter if it's billed as separate folios or a single folio. Even overlapping folios (ie one room arrives before or leaves after others) seems to work for spending, but not for nights credit (looks like it always follows the room with the first checkout)

Quickest way to check is take base points posted, divide by 10, and that tells you how many USD counted.