I have 2 phones on my account. One is mine and one is my sons. Can I set it up to auto pay my bill with my credit card and set my sons to pay with his own banking info? Currently it's billing both to my cc.
Not really. The whole purpose of such account combining was to allow for a single payment instead of multiple payments. Since the name on the account must now match the credit card, etc, the only way to have him pay his own bill, is by having his account independent of yours.
You could have him e-transfer the appropriate amount to your bank account each month, but that's about it.