We trekked East across WA on our honeymoon with the intention of wine tasting in Walla Walla but as soon as my wife started seeing WINERY signs along the way, the detours began and we spent most of our time tasting through the Yakima Valley region instead. On the way back the following day we stopped at some wineries in the Red Mountain AVA. Our favorite was Cooper Wine Company - highly recommend!
But the real reason for my response is to point out the amazing place that we stayed overnight, just West of Walla Walla, in Touchet. Cameo Heights Mansion.