The phrase "windy bombast" could be called redundant. "Bombast" ("pompous or pretentious talk or writing") works as a noun, though, and "windy" ("using or containing too many words") as an adjective. As you can tell from the WR definitions I quoted, there are some nuances that differentiate the two words.
Thanks again. By the way in my native language this word bombast is borrowed from English and sound like original one. It is funny, but I do not know what exatly it means. I think that is some kind of snobish, affected or mannered. So maybe the right translation is snobish verbosity. I know from my rich experience that in such cases where there are many variations, it is imposible to translate the very exact meaning of words. It is important for one to interpret as corret as he can.