If he's having success before baths, perhaps try introducing one more time during the day. Maybe before his nap or right after lunch or something you try everyday. It will become part of his routine.
My daughter started potty training prior to 2, also. She's almost 25 months now and goes on the potty whenever we're home. We put her back in diapers when we go out or for bed or nap times.
We reward with chocolate milk or sugar-free jello. I hear stickers or M&M's work well :)
We keep a kiddie potty in our living room and one in our basement (our two playing areas), and she just stops playing, runs over and goes, and goes back to playing. We're hoping to have her day trained by September, when my hubby and I go back to work.
We just offered the potty every once and while, and she would sit on it and never go. Finally she just started going. I tried the 'once every...' 15 min, 30 min, 45 min, etc. but she doesn't need to go nearly as often as I thought.
Have patience! And good luck!