In my Yes man playthrough I got this pretty much immediately after becoming "accepted" by the legion. I never did anything besides pretend to destroy the machinery and turn in a few dog tags.

Now in my Legion playthrough I've done 3-4 legion main quests, 2 legion side quests, and turned in probably 30 dogtags. I've been "liked" for a long time, but still nobody has come to give me this quest.

Is there something you have to do besides get your reputation up?

Anyone know?

It's part of the main quest, I think it happens after you finish Ring Ding Ding - so it doesn't matter what your rep is, if you're not that far in the main quest yet you won't get the invite.

ETA: Unless I've misunderstood the question, I'm referring to getting Caesar's mark and the invite to visit him...

Main Quest quests related to Caesar boosts you substantially, also if your wearing any faction - including Caesar - armor you do not gain +Rep at all.

Reno

Yeah I'm well into the Legion main quests and have been liked for a long time.

The quest Caesar's Favor given to by the legionary that approaches you and says we capture stuff on raids that we dont use, here is the location of the drop boxes, this quest will reset every 3 days, dont store anything in the boxes. Is that the quest you are referring to?
Or the one where you are ordered to report to the fort for an audience with Caesar?

Yeah that's the one, the one where they give you stuff.

I might just add it with the console, wonder if it respawns if I do a console add?

I got it after reaching idolized rep. (with the legion): after exploiting a bug on PS3 playing hardcoe Mode. If anyone is interested on doing this: Just keep teaching Decanus Serverus how to neutralize NCR landmines, you will get 50 exp. points and rep. gain with the LEGION without damaging your NCR status, each time

During the dialog options with Serverus just keep asking about the NCR situation, then after his answer select other questions and the speech challenge will keep showing up (you need to have at least 50 points on your explosives skill)

After I found this glitch manage to level up 3 times after I got really bored (from level 25 to 28) but I think that you can keep doing for as long as you want.

Already got this Quest twice and it keeps appearing near the Sniper's Nest. You get tons of ammo, bunch of misiles, adv. rad suit, leather armor,some guns and like 400 Denari. Just pick up everything and walk back to Sniper's Nest and stash watever you don't need there.