For anyone else who is encountering the bug that setting a phone number as the phone contact for more than one Atmos account results in the Alaska telephone system failing to recognize your account number as valid or failing to recognize you as elite (I've had both but more recently the former) I've confirmed that using a Google number for everyone else will half fix the problem.

Whoever uses a unique phone number will be recognized as will their status and you'll be routed to elite reservations (less wait time). Everyone else is out of luck.

Fixing it for them requires setting up a unique Google phone number (forwarded to your shared phone line) for each Atmos member.