The weapon property bane is a wonderful boost to a weapon on the occasions where its the right bane. One effect is that the weapon enhancement is +2 than what the weapon states, so a +1 bane (human) sword is actually a a +3 weapon against humans. But when dealing with creatures that have DR, the difference enhancement levels matter for overcoming DR, and other sources like magic weapon greater while increasing the enhancement, do not affect DR.
from magic weapon greater
This bonus does not allow a weapon to bypass damage reduction aside from magic.
Since the weapon property doesnt have the same wording as the spell, my thoughts are that it would be effective against higher DR types, but I have nothing to stand on for this.