What Medievalist and mgoblue said. If the guy owns the place and it's a high-end restaurant, he would have a sommelier. If he's a snooty guy, I'd consider taking the route that mgoblue suggested. And as others have pointed out, the wines in the restaurant will definitely depend on the kind of restaurant it is.
The wine world is so huge that trying to select a wine that fits into your story would take a lot more research. There are some wines that have snob appeal because of their long histories (e.g., Chateau Petrus, Chateau Lafite), wines people get just for the name even if they know nothing about wine (e.g., Dom Perignon, Cristal), cult wines that are extremely difficult to get because they're made in such small quantities (e.g. Screaming Eagle, Silver Oak), under the radar wines that only people "in the know" know about (e.g., smaller boutique wineries), etc. In other words, if you really want to dive deeply into this, the kind of wine the snooty guy orders can depend on the reasons
why he's snooty (truly knowledgeable, poser, show-off, big spender, etc.).
Can you tell I'm overthinking this?