Just in case it wasn't clear, "bank" makes aaspend wait until it has that many aa's to spend any.
You can use /aaspend brute now to make it buy something immediately with what it has, if something is available. Brute now is also nifty to see if aaspend is having an issue. I noticed the enable/disable AAs can trip it up sometimes. I've had to manually buy those on pretty much all of my toons.