How much wine?
If you drink wine very day, the calories can certainly add up.
Red wine has about 150 calories a glass, and white has around 84. Here's a site where you can check further: http://caloriecount.About.Com/calories-wine-ic1410
if you drank only 2 glasses
of red wine a night, that's 300 extra calories a day. A pound of fat = 3500 calories, so you'd gain a pound about every 11 days at that rate.