We have Starwood Gold and have used it for hotel rooms, but never at Vistana. It gets us better rooms and early checkout at hotels, but these aren't really options at Vistana. If you are requesting certain features, you can call ahead, and they will try to accommodate you, but I can't see the gold card making any difference to this.
But of course, it never hurts to try. Let us know if it does make a difference.