If you are following a plan, then Weight Watchers Smart Points is 4 points for a 125ml glass and Slimming World is 5 syns for a 125ml glass.
If you are calorie counting then there are 86 calories per 125ml glass, or if you go for one of the reduced sugar varieties, it's around 67 calories per glass.
To give this some perspective, the below is a rough guide on calories in other wines too -
125ml Red Wine - 85
120ml Dry White Wine - 77
I hope this helps a little, and cheers!