Well, I can see a large number of issues involving a flying alien:
1) Any avian creature's arms and hands ARE its wings, so in essence the xenomorph would have to have only one or the other
2) Most flying creatures are only capable of flying because of feathers. Since xenomorphs do not develop hair of any other follicle-based structure, they would most likely not develop feathers.
3) In order to fly the xenomorph would be required to have hollow bones or be incredibly small in size. Since xenomorphs possess multiple appendages and are plated by bony protrusions beneath the skin, it is highly likely that they would simply be too heavy.
4) Most flying organisms have to be taught how to fly. A xenomorph would have to somehow instantaneously gain this knowledge through instinct.
As previously mentioned, I doubt that a xenomorph would ever develop wings if it emerged from any sort of airborne organism. And, as previously mentioned, I believe that it would simply adopt an airborne host's advanced circulatory system, light frame, and angular skeletal structure. This is the same thing I did for my personal xenomorph Crow. If you would like a reference picture, I have one in my Profile.
"If anything in this life is certain, if history has taught us anything, it is that you can kill anyone." - Michael Corleone