I don't know if she's more powerful than Revan (no one said this). I tend to believe that her character was based on Anakin Skywalker type of a Jedi (young, ambitious and agry) and Revan on Exar Kun (allpowerful mastermind) that's why I think that she didn't show her entire potential. All that talk about her greatness and importance reminds me what we hear in prequels about Anakin.
Notice one more thing: in every duel with Revan (except first) Bastila is heavy exhausted. On Rakatan Malak send her shortly after brainwashing tortures that damaged her health, and on Star Forge she entered the fight straight from the state of Battle Meditation that was described as very exhausting and requiring great concentration. Revan on the other hand was in good condition. That leveled down her padawan abilities even more.