No, it cannot be done. Amex does not do joint accounts at all.
Ah, so I have been mislead.
This causes a major PITA for BofA online banking, as it won't link an e-bill to account that is not the same primary card holder as the primary account holder of the bank account.
Does anyone know if it is possible for, say, a BofA Visa to be made into a joint account?