I dont know a lot about that subject but mabey this little bit will be insightful.
The seeds and skins of grapes contain an antioxidant called Resveratrol. Blueberries and other dark fruits also contain a similar amount of resveratrol.From what I have studied there isnt a significant difference in amount. However, there is a greater amount of information on wine made from grapes due to the popularity of traditional grape wine over wine made from other fruits. So in a nut shell... there is a lack of studies to support any real answer to the difference.
They both contain more healthful antioxidants than beer and that works for me!