BY ALEXANDER MARTIN REMOLLINO Bulatlat.com Dr. Bienvenido Lumbera, literary scholar, social commentator, librettist, and poet has been chosen as 2006 National Artist for Literature. He fully deserves the award, and more so than many of those who had received it ahead of him. It is now official. Dr. Bienvenido Lumbera, known as Ka Bien to…