Bob Anderson, a 28-year veteran of the Bay Area TV market, plans to step down as president and general manager of KBWB Channel 20 at the end of the third quarter, station owner Granite Broadcasting Corp. has announced. Anderson had been at KNTV Channel 11 for many years, and when Granite sold that station to NBC, he decided to take the helm at the company’s other Bay Area station, TV20. Programs he created and launched at Channel 11 include “Tech Now,” “Sports Sunday” and “Wine Country Living” (which is now being syndicated nationally as “In Wine Country”). At TV20 he created “Your Green Report,” and a half-hour lifestyle program called “Your Green Life,” which will soon be expanded into a weekly program. Anderson hasn’t announced his future plans.