The active ability of the Hatred Domain doesn't do anything, when targeted on a creature it simply activates without adding any of the bonuses: Once/day, target a particular enemy to gain a +1 AB bonus and a +1 Negative Energy damage bonus, both versus their racial type, that last for one round/level.
Have you set the ability through the player tools menu? Or are you using the domain ability in your radial menu? If the latter, you'll find that it doesn't work. It's the same thing with all domain abilities, you will have to set them to a player tool before they work :)
Sorted, thank you.