I have to confess that I've never used the wide and tele adapters, as they don't seem that effective, but your shots look good, so I'll have to try them out.
About your film, I'm not sure if I understand you correctly, but if you have overexposed by a stop, your grain should be a bit finer, unexposure on colour negative film will make it grainier. It is likely due to the incandensent lights on daylight balanced film.
Modern colour neg film is very tolerant of overexposure, and half to a full stop will make it finer grained. The way this works could likely fill a book, but briefly, this is how it works. There is a high speed and a low speed emulsion combined together in the film, so that when the film is underexposed the high speed emlusion is exposed, but when overexposed only the low (fine grained) is exposed. This is what gives this type of film its' great exposure latitude.