The planned Ponce de Leon Towers in Coral Gables got its first tenant, New York-based Rockefeller Group Business Centers, which will take a full floor in the 215,000-square-foot Allen Morris Company building. The tower is set to open in early 2011, at 2801 Ponce de Leon Boulevard,. as part of the seven-acre Old Spanish Village. Construction begins next year. Full occupancy at the Allen Morris Company development Alhambra Towers, another luxury office building, supports some observers’ belief that businesses are willing to pay for upscale amenities, and say the Rockefeller Group’s lease bolsters this conclusion.