Living in California, we are lucky that no matter what city we live in, there is a wine region in our backyard. San Francisco has Napa and Sonoma, Los Angeles has Santa Barbara, Orange County has Temecula and San Diego has the Ramona Valley.
Yes, there is a wine region in San Diego County. In 2006, the Ramona Valley AVA was the 162nd area to be designated as an American Viticulture Area. It was only the second AVA to be designated in San Diego County (San Pasqual Valley was designated in 1981) and the third in Southern California (Temecula Valley was designated in 1986). These three AVAs all fall within the large South Coast AVA, which covers all of Southern California south of Santa Barbara.