When you are attacking a target with light attacks the bleed damage never occurs.
When you attack with a light attack it applies a bleed, When you constantly hit with light attacks however the DOT never applies its damage, it is being refreshed entirely each light attack before the damage occurs completly negating the effect of the bleed on light attacks.
the Bleed is nice when you stop attacking to let it actually occur, my WW was getting 221 crits from the bleed. but the key of DOTs is that they do damage when you are attacking... right now there is no benefit from the Bleed.
I play every class in every situation. I love them all.