Sharing Dining plan credits and tipping

If we use our dining plan credits for a meal, can a guest with us who does not have the dining plan use their magic band to pay the tip on their credit card?

I don’t see why not

Yes, are you using your credit for that guest?

I will be using my dining plan credits for that guest.

I would tell them that is what you want to do when they ask about how you are paying.