Nope. All cards will have access to all credits.
And trust me, I have had plenty of sessions of scolding (adult) travelling party members for using snack credits for things like bottled water (especially when we were all carrying water bottles in the first place).
What has seemed to work best for us is to tell everyone: Look, you have one snack credit per day. One. Per day. Please use one every day. If you share snacks, fine, but use the other person's credit on something else later. If you are not hungry, fine, buy something that will keep and bring it back to the room.
At least that way we make sure that everybody gets to use their credits, and nobody can accidentally spend seven of the others' since they know they have one to use for themselves, period. It's a little rule-heavy, but it is the only thing we've ever come up with that keeps the credits available past about day three with a large party.