Bruce has better feats of resisting harm. If the characters were given their equal due respect, Frank would be able to take more overall harm before falling. In rpg terms, Batman has higher natural armor while Punisher has more hit points.
But that might just be my headcanon. They don’t get equal respect and so, just by volume of feats, likely edge to Batman.
Apparently, Batman is more durable, because he has more showing and training. Though Punisher himself has plenty of durability and endurance feats too. Like, staying under a car while injured when car is moving for a long distance.