No, it is one credit card on file per unit. However, if the other people wish to use the room charge, and you are comfortable with it, you can get a print out from the front desk the night before you depart and break down their purchases, then they can go to the front desk and pay that portion with their credit card. You may need to take your credit card, also. The front desk may need to swipe it again to charge out the remained of the balance the next morning.
I agree, it is always a good idea to carry an extra credit card, just in case the resort computers go down...it could disable charging on the kttw cards temporarily.