Fatebot with Agil, Zekken, and Patrol Plugins keeps you killing, repaired, and wont stand in shit, make sure you blacklist any fates that will get you or your raptor chicken killed and go to town. Previous to Kagami's post of the 15-50 profile I would quest my chars to obtaining their choco's hit up the companion quest and make sure that they were leveling them through each of their combat classes.
I don't know how much xp you'd get, but you can find areas where there are pockets of inf respawning wisps and their higher lvl brothern. However you just want to make sure you don't run out of MP (above methods are more proven and a good profile can easily be afkable - well fates drag you into odd places sometimes but still).
I just turn on the summon chocobo option in the Ultima combat routine and summon it everytime I am leveling up. When you go through a few characters it should get it to a pretty high level. If you're looking to just level the chocobo I would park my fatebot in a highlevel area.
