Tested in 15w49b. Potion arrows, along with spectral arrows, are consumed from the player's inventory when using a bow in creative mode.
Works fine for me, you just need to keep searching, they're about as rare as a village.
Confirmed for 1.8 pre-1
This happens on pickaxes also (only tested on diamond).
Confirmed for 14w32b
Just use Ctrl + middlemouse and it will give you the banner with NBT data.
Reproducible in 15w49b.