The bartender is a test bed for all AI in game.
I can tell you more for what the devs wants to achieve with the bartender but not all those features exist yet in the actual bartender. I will try to test which one have been done.
The bartender manage real stocks (bottles in fridge for instance). Every element used is counted. If the fridge is empty he should say he can't do your beverage and launch restock order to the server (the bartender AI will do it, not a script tied to the fridge)
He had no scripted routes. He will search the fridge and go to it by himself from where he is when needed. When he takes your order, he should seek you to give it to you when done. If you have moved and took a sit 5 m away, the bartender have to detect the small door closing the bar, open it and pass the bar to give you your order. All those events not predefined. He have to recognize all its surroundings, don't collide with others NPC/PC and put the bottle in the right place where you are (the table if you have take a sit for instance). He should be able to get back the empty glass too.
When you command a multi elements beverage, he doesn't execute a full script but follow a recipe (whiskey, next ice cube, next water). The animation suite is dynamicaly launched.
A part of the animations are not in mocap or hard scripted but calculated. Ex : the movement to the fridge should be natural from 2m, 2.1m, 2.2m, 2.3m, 2.4m, etc (no moon walk). I have a good video about it from SQ42. I will post it later.
He constantly detects pnj and players in its surrounding and their localisations. For ex, if you pass behind the bar, he shouts at you to get out (seen in video).
He will be able to show emotions and analyze you. If you stink (no shower since several days), he can refuse to serve you.
He can queue orders. If 2 npc ask beers before you, you have to wait, you will be the third to be served.
The bartender and the NPCs will interact by themselve. We should see bartender getting orders from NPC.
He can be used as a mission giver or receiver and should have a good stock of sentences to say.
That's the plan. Dev have said that some of those features are already used for combat. For instance NPC will seek soon for ammo box when out of ammo (shown in video).