According to the screen grab, as well as their circular (which also lists Wii Fit as eligible), Toys R Us should be including this in their sale. So when reader Zachary showed up without either, they would not allow him to include Wii Fit into the mix. Your best bet, both Zachary and our eyes, is to go down to your local shop with one of these in hand and, if they aren't willing to comply then, always ask for a manager. Hopefully he/she will be a bit more knowledgable than the regular staff.
Oh, and if you're looking for another game to pair up with Wii Fit, we'd suggest you check out Boom Blox.