France has its appellations d’origine contrôlée (AOCs). Italy has its denominaziones di origine controllata (DOCs). The United States has its American Viticultural Areas (AVAs). All three regulate the areas in which grapes that go into designated wines may be grown: a Pauillac must be composed of grapes grown around the village of Pauillac in the Bordeaux area, a Chianti must be composed of grapes that are grown in a particular region in Tuscany, and a Lodi wine must be composed of grapes grown in the Lodi AVA near the city of Lodi, California. All three systems are hierarchical, too: the winemaker in Pauillac could label his wine as Pauillac or Haut-Médoc or Médoc or Bordeaux because Pauillac is in the Haut-Médoc AOC, which is in the Médoc AOC, which is in the Bordeaux AOC. Similarly, a winemaker using grapes grown near Healdsburg, California can label the resulting wine as Alexander Valley or Sonoma County or California. All three systems (and the others like it in other wine-producing countries) are intended as truth-in-labeling measures: you simply can't call a wine a Bordeaux if it isn't produced with Bordeaux grapes, and you can't say that a wine is from Lodi if it isn't.
There are a couple of key differences, however. The American AVA system only regulates the location that grapes can be grown. A grower in the Lodi AVA can grow whatever grapes he wants with whatever techniques he wants to whatever yields he wants and vinify it however he wants and still label it Lodi. Not so with the Pauillac grower. If he wants to label a red wine as Pauillac, it must be made from only Cabernet Sauvignon, Cabernet Franc, Malbec, Merlot, and Petit Verdot grapes with certain yields and made with certain techniques. Furthermore, the finished wine must taste like a committee thinks a Pauillac wine should taste enough. In other words, the AOC system (and the DOC system, too) is designed not merely to guarantee the place of origin of a wine but also a wine's character. Secondly, it is rare for a winemaker to choose anything but the most specific AOC or DOC that a wine can qualify for. If a wine qualifies to be labeled a Pauillac, it would be exceedingly unusual for a winemaker to label it as a Haut-Médoc. That isn't always the case with AVAs. The Lodi AVA, for example, has a number of sub-AVAs (the Alta Mesa, Clements Hills, and Jahant AVAs, among several others); but it would be perfectly reasonable for a winemaker located in the Alta Mesa AVA (and making wines from grapes grown exclusively in that AVA) to choose to label his wines as Lodi. That's because consumers know Lodi and what to expect from wines bearing this appellation. Not so the Alta Mesa AVA.
I don't know if the Ravenswood Lodi Zinfandel could have qualified for another sub-AVA appellation, but it really doesn't matter. It wouldn't have fit in with the marketing plan for it to have been anything other than Lodi. As I have written previously, this is my least favorite of the three 2005 County Series Ravenswood Zins that I have tried (the other two being the Sonoma County and the Napa County). It's just too jammy and cooked-tasting. That's not to say that I didn't still enjoy it, just that I would pick either of the other two to buy again before this one.