When a June 28 Greek Theatre concert by Tori Amos sold out swiftly Saturday morning, a June 29 show was added. Response was so good that a June 30 was added as well. As of Sunday, tickets to the two new concert dates were still available. . . . Slain singer Selena was honored posthumously Saturday at the Tejano Music Awards in San Antonio as female entertainer of the year and best female vocalist. Awards also were given for her song "Tu Solo Tu" and her crossover album "Dreaming of You."