Although Napa and Sonoma, 50 miles away, produce some of the world’s best wines, a new high-end restaurant in San Francisco’s Inner Richmond District will concentrate on difficult-to-find wines from Mexico. The restaurant is taking over the premises at 431 Balboa Street, the old Sushi Bistro establishment, which transferred operations across the street. Cantina Los Mayas debuts on July 14th and advertises itself as “the very first Mexican wine bar to open in the United States.