Hi Heather,
Thank you so much for visiting the Disney Parks Moms Panel with your question. A two-bedroom villa is a great way to travel with extended family. Both you and your brother will have your own space with your families, and then be able to come together in the living area and kitchen. I have done this often with extended family, and I find it a wonderful way to vacation at Walt Disney World!
I have good news for you. You can in fact link different
MagicBands for guests within the same villa to different credit cards. You will need to do this once you arrive at your resort. I find that the easiest way to do this is at check in. My family recently shared a Treehouse Villa at
Disney's Saratoga Springs Resort & Spa with another family. When we arrived at the resort, we all met in the lobby and presented the credit cards that we each wanted our MagicBands linked to to the cast member there. The cast member was able to link my family's MagicBands to our credit card and my friends' family's MagicBands to their credit card. Throughout our vacation, we each used our MagicBands for charging, and at the end they went to the credit cards we had linked at check-in. It was easy!
I hope that this information is helpful for you, Heather. Have a wonderful time planning your magical vacation, and please do let us know if you have any further questions.