@rocksolid Since you are the main account holder, as long as you are signed into your upgraded account on your device, you should be able to enjoy the full benefits of your subscription.
Could you confirm that you are logged into your upgraded account on your device?
Sometimes, it may help to sign out of Pandora, and then sign back in using the email address associated with your upgraded account.
For the additional accounts you've invited to your family plan:
Our support team has informed me that although you've sent out the invites to multiple accounts, no one has accepted the invitations to join yet. Have them locate the invitation that was sent to them via email, and go through the steps to accept.
In the meantime, our support team has also confirmed with me that they will be sending you a separate message via email at the email address your Pandora account is registered under.
Please keep an eye out for their message, and they will be happy make sure you get properly set up with your family plan subscription.