How does Enlightened Spirit aura interact with Barbarian Rage?

[HatsuharuZ]

The subject is the title.

I'm running a warlock life; my last life was that of a paladin. I'm statted in such a way that lends itself to fighting in melee as an STR-based ES. I'm only at lvl 6 now, but I think I'm going to multiclass once I reach warlock level 12. Does anyone know? The wiki doesn't say anything on the topic.

Also, I usually go pure-class, so I don't know much about multi-classing or interactions between the class features of different classes. I know I could get everything I want out of one level of fighter( access to better armor and weapons), but I'm wondering if there are any other interesting multi-classing possibilities I could look into.