Pepe Botella has hit on a fine formula for success. As good in the hours around midnight as it is in the afternoon when its wi-fi access draws the laptop-toting crowd, it’s a classy bar with green-velvet benches, marble-topped tables, and old photos and mirrors covering the walls. The faded elegance gives the place the charm that has made it one of the most enduringly popular drinking holes in the barrio.