Looks like others had the same response as me! I had the same problem with my daughter, but had just turned two. The phase lasted a 2-3 months, and she is back to loving bath time. I recommend kids bubble bath, toys, new things to get her in there. Rotate new toys with old toys, then rotate the old toys back into the routine. That way he does not get bored.
I find that distractions work too with getting her into the bath. When she was throwing a fit outside the tub, I would be kneeling at the bathtub, splashing around, making a boat or something out of her foam wedges. I would then make a big deal about my cool boat and she would want to come see. She would then get caught up in the excitement and forget her fit.
Good luck!