My wife looked into this, you can only put a wrap on a vehicle that's totally rust-free, which even for nice southern vehicles is not usually the case. Also I think it was going to cost upwards of $8000 to wrap a 35' bus.
So I wouldn't recommend it. Take a weekend to prep, mask, and paint the bus (from what I've seen 80% of that time will be in the prepping and masking). We're planning to do ours next year, likely using a paint sprayer with Rustoleum or similar paint with an added thinner and hardening agent.