This is a great question, kingofhearts. However, I'm not completely sure of the answer, so I'd like to reach out to our team for complete clarity. I'll let you know what I'm able to find out.
Hello again, kingofhearts. I've heard back from our team and they were able to share the following.
Earning points for the stay booked on upromise.com depends on how Upromise is booking the reservation. If Upromise uses a third party system (like Expedia, Travelocity, hotels.com etc…) they would not get their points. If Upromise books through a Marriott channel they would most likely earn points for the stay. If you have a current booking, we can look into it for a more definitive answer, just send me a private message with the details.
Let me know if you have any additional questions.
Thanks very much for checking on my question concerning Upromise. The Upromise links directing into the Marriott website, so based on that, I probably would receive credit. I haven't tried it yet, but when I do, I'll let you know the results.
Have a great holiday,