Bonjour Michel! Welcome to the Disney Parks Moms Panel!
If I understand your question, you are a party of 4 all staying in the same room, 2 of which you would like to manage their own
Disney Dining Plan. If this is correct, then as long as the
MagicBands are linked to the account, everyone will have access to the Disney Dining Plan credits. That means if 2 of you go for lunch at
Cosmic Rays Starlight Café, and the other 2 prefer to go to
Columbia Harbour House, you can each redeem your 1 Quick Service meal. There is no need for the entire group to be together to use the Disney Dining Credits. Of course, as you mentioned there are 4 adults in the room, I am assuming that your children are adults as well.
I hope this answers your question and remember that you can also visit us to
ask your questions in French at the Tribune des mamans des parcs Disney!
Bon appetit,
Jen