Since a pre-paid MasterCard works in a similar fashion as debit and gift cards, the answer would be no. If you don't link a credit card to your band, you cannot use the band for charging.
Actually, I've almost always used a debit card (with a MasterCard logo) to open my room charge account. Since they don't put a hold on the card and only check to make sure it's a valid account (by running a transaction for $0.00 which sometimes results in a few banks putting a hold of $1.00 on the account), there isn't really a way for them to know whether it's a regular credit card or a debit card. I'd presume the same would apply to a MC/Visa-logo gift card.
Any problems would come when the resort tries to charge all built-up charges to the card (whether that's mid-trip when they hit the pre-determined $500/$1000/$1500 limits, or the night before checkout when all charged are pushed to the card on file). If the balance on the room account is more than is available on the card on file, you'll get a call from the front desk (and I presume also a note under your door) asking you to stop by the front desk and settle your account. You can tell them to charge $xx.xx to the card on file and then give them an additional form of payment.
The same would also hold true of opening a room charge with a credit card that only had $300 worth of credit, but charging $400 to the room charge. When they tried to dump $400 onto the card, it would come up as over-the-limit and refuse the transaction.
Note that you can't give them multiple gift cards up-front, though. It's one per room charge account. So say you have five $100 MasterCard gift cards. You couldn't give all five up-front to cover $500 of your room charges. (Although you *could* open up separate charges per person, giving a different gift card for each person, but that starts to get complicated)
-Rob