If you are going to buy a package from Genting, you can tell them over the phone you have platinium card. They will give you the Silver card which according to bro silverwolf, you can then happily flash at RWS to get your RWS silver card.
I suppose I would use the word "sucker" when I see a well off Singaporean using one of the those green Genting cards.
Hmm ...well I have to try it out in Genting then.