I don't know if you've done it yet, but you can get a cape with up to +50% capacity points bonus on it at all times (which will stack with other things) via the Incursion content. Some in the linkshell run it from time to time, its also nice for gil.

There are also many permanent bonuses to capacity points you can acquire- Completing all of the Wildskeeper Reives, completing Lair and Colonization Reives in each Audolin area will all award you permanent bonuses, and there is a permanent bonus unlockable from every storyline: The three nation's missions, each of the expansions' missions, and Rhapsodies.

Not to mention you gradually gain more Capacity points the more job points you spend on a given job.