California olive oil was the laughingstock of the olive oil world for a long time; despite our climate being absolutely perfect for olives, the oils ended up being acidic and sour, and chefs ignored them in favor of expensive imports. Fortunately, the quality has taken a marked turn for the better in the last 10 years, and olive groves have been installed in quasi-coastal areas in places like Ojai and Temecula.
Temecula Olive Oil's store in downtown Seal Beach, next to Slice of New York, is built along the same lines as nearly every other olive oil shop in Orange County; a tasting bar that has regular and flavored oils and a set of sugary vinegars labeled “balsamic”, but with the addition of actual olives and olivewood products, and the usual ceramic pouring bottles and dipping dishes with raised bumps for grating garlic.
The three standard oils available at the tasting bar were from the 2010 and 2011 harvest; the fall harvest is underway, so new olive oil should be coming soon. (Olive oil is at its best within six months of pressing.)
The Temecula Valley blend had that tannic acidity that characterizes a lot of California olive oils. Better was the Rotture di Oro, which was mild and buttery, and Le Caprice de Nature, which was the best of the bunch. These are oils to use raw, not to cook.
While I'm normally not a fan of flavored olive oils–I prefer to create my own flavors and use really good olive oil as the base–I will say that the basil olive oil was one of the better flavored oils I've had in a California oil tasting room. The staff said the basil plants are crushed in the press with the olives; it tastes like liquefied caprese salad.
Unfortunately, what the oils are is expensive; half a liter of unflavored olive oil goes for nearly $20, and the reserve oils are the same price for an even smaller bottle. Still, that's the going price for local oil, so it's not out of range; use it sparingly.