I find it really weird that they wouldn't let you...I booked 2 reservations on a 40% pin code for my trip two weeks ago at the Beach Club, and once the reservations were booked we were two completely separate travel parties - they had their own reservation numbers, their own credit card on the room, their own KTTW card, etc.
The only thing that was important was we all needed to be on either a room only or a package, it couldn't be one or the other, and we had to be at the same hotel during the same time. My friends briefly considered switching to Poly from BC and they couldn't if they wanted my discount.