I have been able to get the $1 a gallon deal on tanks 20-55 gallons. That's how I bought my oceanic 33 gallon cube last year.
The ad only limits the special on tanks on-hand between 20 and 55 gallons (no special orders, no kits or combo tanks). If it's a tank between 20 and 55 gallons, doesn't come in a box, or associated with a stand, light/filter combo - I would call it fair game. I don't even recall bow tanks as a restriction. If an employee says otherwise, I would ask to have them scan it anyway.