Bus's should have those racks on the front like they do in just about every other country. Sure you only get 3 or 4 on there, but really useful I think!
Trains too, virgin pendelino's officially only have 3spaces, though if you actually try you can get 6 on there safely without impeding the drivers exit.
National express/ megabus don't let bikes at all unless they are packed up (so that they cannot tell) because if they suspect its a bike in a cardboard box/dedicated box, they make noises about it/ deny entry.
I can often get a national express to london with bike in the hold from local town pickup, but its almost impossible to get the bike back OUT of london as it means getting on at Victoria where the super fussy lot are.