Inconsistent, maybe, but Teagarden career minor league OPS stands at .899, with an insanely high OBP. He cranked out 6 HR's in a brief cameo in the majors, and plays very good defense behind the dish.
The Red Sox have a surplus of young pitching, and really not much to speak about in terms of young catching. Even if Bowden is the better bet, which is debatable, the Red Sox should still take the risk, because Teagarden could be an impact bat at a very crucial position for a long time.