This is your best option. It all depends on the hotel and how they "process" the reservation.

I've had stays with lots of rooms (i.e. 20+) where I knew I couldn't get points for all the rooms. I've asked hotels if, even though I was paying for all the rooms, they could put other names on some of the rooms to allow them to get some points (up to 3 rooms per night.) Some hotel were just fine with that and we had no problems. Other hotels didn't want to (or the front desk person didn't know how to.) In these situations, I would ask and if they said yes, I'd give them the other names and MR#s and thank them. If they said no, I thanked them as well as they don't have to and arguing most likely won't change anything.

If I remember correctly, I think non-FS hotels (RI, CY, SHS, FFI, etc) seemed more likely to say "yes" than the FS hotels (MR, Ren, JW, etc.). It can't hurt to ask. Just be able to accept "no" as an answer.