Housing helps for chocobo exp but not necessarily - the most exp u'll get for your bird are the two chocobo agendas (kill 10 mobs and kill 100 mobs with your chocobo in party). Sadly they patched the agenda requirements - only fate mobs are taken for the killcount now but that still works fine.
If you are more the "soloist" you should give your bird some serious love - he'll be a great help. Jupp. :3
