We just booked 2 placeholders onboard this past weekend, they did make me put one in my name and one in my husbands, even though we always book 2 cabins and the other is for our adult daughter and son, who were onboard with us, but we do put both rooms on my credit card. I used the placeholders yesterday and while it is a strange workaround, they did put my adult daughter and I in one cabin and my husband with grandson in the other, even though we always sail together and are platinum. But I like having both bookings linked on my credit card so I am sure the room stewards will be used to this by the time we sail. It is convoluted and we never did it this way before, but they said we can just put whomever in each room as long as the person on the placeholder is aboard.