Not the tile guys fault you purchased and installed the least expensive bath tub on the market. The tile could have been cut to address the swoop but only if you would be willing to pay for the additional time required to close the gap.
I'd say caulk it and forget it.
Why don't you take those bull-nose pieces and cut them at the bottom to fit the goofy tub? That way the bull-nose (tops) of each tile could be as straight as the tile is and the bottoms of each tile would follow the curve of the cheap tub.