RANDALL GRAHM is a changed man, again. But this time he thinks he means it. Those who have followed him on his 25-odd-year journey as winemaker, jester and all-around philosopher king of Bonny Doon Vineyard have gotten used to the periodic pivots that twist his vinous trajectory like one of Escher’s Moebius bands. But then, straight lines never really fit the Bonny Doon aesthetic. Since its inception in 1983, Bonny Doon often seemed one step ahead of the rest of the California wine industry, yet incapable of prolonged focus. Mr. Grahm began with a fascination with pinot noir. He became a leading voice in California promoting Rhone grapes, and then, just as vigorously, touted Italian grapes, the obscurer the better. There was riesling, too, and delicious sweet wines. At its peak, in 2006, Bonny Doon sold some 450,000 cases of wine, more than 5 million bottles. But, as anyone so philosophically inclined might wonder, what did it all mean? Mr. Grahm, 56, indeed asked himself that question...