Jean-Paul bunq Pack and bunq Joint are two separate memberships, they can not be combined. You can not be in both together. Every individual can only have a single membership.
When you intended to ask whether you could have a Joint bank account as part of your bunq Pack membership: definitely yes! 🙂 Please note that "Joint" is used to refer to a type of bank account, but it is also used as the name for a membership. (not super convenient). 🙂