Just to give feedback here after my stay - I did get points, and elite nights for my stay at The Renaissance, booking over email using the Entertainer App rate.
It was a bargain as I had booked two rooms for two nights (came up to £80/night including taxes, per room, including breakfast) and I think because they were running at full occupancy they upgraded us to a two bedroom private pool villa, the only one on the property. Right by the beach and pool, and with a private pool too and a separate living room. I only have Marriott Silver, so wasn't expecting this!