I have read somewhere, can’t recall at all where, that although Bastogne was something of a transportation hub, the Germans did not consider capturing it a strategic necessity.
They had decided to just bypass it until it got the publicity, then Hitler ordered them to take it.
You are correct — the Germans were trying to capture the Meuse and control the waterway to the North Sea. They didn’t have the supplies for an extended assault to take Bastogne, so they figured they’d bypass the city and take it at their leisure after Bastogne ran out of supplies. Unfortunately for the Germans, they did not count on the efficiency of the American airdrop, the resiliency of the 101st Airborne, nor the determination of Patton and his men to cover 100 km in 3 days.