If you and your partner hold different accounts at one bank, you may have different user names to access the accounts online. You can still set up both accounts to receive online updates in Money. Because there are two user names, the bank will be listed twice-once for each user name-in the Money account list.
If you want to use only one user name for both accounts, contact your bank to see if they can link the accounts. Then, you can update both accounts in Money using the same user ID and password.