There are currently 4 maps for Zombies mode in Black Ops 2.
Nuketown Zombies.
Green Run. Green Run - Bus Depot. Green Run - Town. Green Run - Farm. Die Rise.
Green Run, Nuketown Zombies, Die Rise, and Mob of the Dead are the Map Names- In the case of NZ, DR, and MotD Treyarch has always referred to these three as maps and never as gamemodes or anything else. In the case of GR, TranZit was always referred to as a gamemode, so Green Run had to be the name.