One way to unleash your inner wine wonk is to take a class, and, as it happens, Gabriel's Superstore in The Vineyard on the dreaded (but admittedly happening) Loop 1604 has just the deal for you: free. The wine education classes for April and May have been announced, and the schedule, running from April 21 to May 26, includes such topics as Old and New World riesling, regional shiraz, and dry rosés. All have been visited to one degree or another by Omniboire, but, hey, we always have more to learn. (Considering our On the Rocks column, you might even find us at the aperitifs class on May 12.) According to