Ok so I rescued Benny from the legion, But were does he go? Once we got past the draw bridge he was gone he didn't die and I have installed yes man on houses main frame, upgraded all securitrons. I was hopiong we could partner up.

You can't, he disappears completely.

Yeah, svcks. I'd love to partner up with him.

Yep, Obsidian really screwed that one up.

A gamey and admittedly inelegant solution to signify that he left the Mojave, I assume. I don't see why not giving you the option of partnering with him is "screwing up" though.

Totally Correct, I would say he left because he is scared of You, the Legion and Mr House. So he when somewhere out West (not were he really when) and is now on the run.

Its a loose end, They should at least explained it in the ending wrap up scenes. And its perfectly logical for there to be an option to partner up with him in this game.Its just Lazy story telling.