in order to bypass the patch, you would need to delete your game data utility, which will delete all the map packs. so, unless you want to have to redownload them all over again, this is not recommended.
the only way you would be able to play bypassed on all zombie maps is if you deleted game data utility, redownloaded the maps, and then bypassed. but the problem is as soon as you wanted to play with friends on the patch again, you would have to download the patch again, which is becomes an integral part of your game data, and then the next time you want to play bypassed, you would once again have to delete your map packs...
quite a HUGE hassle for something that isnt that great IMO.