<<Disclaimer:  Verify this information before applying it to your situation.>>

This is just something I remembering over-hearing at a celiac meeting re; wine.
We were told to be careful about wine, not that alcohol was used to boost it
but that sometimes yeast was used to help the fermentation.  If the yeast
was not GF this is what could be affecting those celiacs that react to wine.
I myself have no problem with white wines (and I lived in Germany, where
wine is something of a staple).  It was also suggested that this procedure
was used more frequently with red wines, which I do have a problem with,
migraines most of the time.  Maybe if someone has more info on this topic it
would be helpful.