Be aware it is a "3 year sample membership"
I have not read the rules more closely and I do not know if it could be added onto an existing membership or not.
Looking at it now, it appears to be a seperate, stand alone, contract for 3 years at the Villas at AKL.
It is also limited in the sense that the contract does not give member discounts, early booking for the member cruise, and a number of other things. It does appear that borrowing and banking is allowed.
I gues you could use the contract you already own and the one you win at the same time. You would just have different reservations if using points from both.
-dave