All wines have acid in them and acid brings out more flavors in food. The acid in wine causes saliva to increase which in turn starts breaking down food in the mouth to release more flavors. That is why wine enhances food so often.
This does not mean, however, that all wines are perceived as acidic. In general, wines under a pH of 3.4 are categorized as acidic, and at 3.4 and above they are categorized as low acid or nonacidic, or savory even though by pH they are still technically acidic (pH <7.0)