You have to be a registered resort guest to gain entry to SAB, everyone will be scanned it to prove they’re staying at the resort. So as @thebeachclub said, they have to be listed on your reservation. If you have capacity on your reservation, you can add them so they can get in. Are you at BC Villas or the hotel? If you’re at the hotel, don’t forget the extra charge for more than 2 adults in the room. And you can ask for key cards for them, so you don’t have to worry about fooling with their magic bands at 2 resorts.