It might be best if you were going to rate a winery you should ask questions, consider circumstances, and understand the history and mission of the winery. Blasting you personal feelings on Yelp is not the way to get the attention of management of what they're doing, or in some cases, not doing. Most wineries have an email account called firstname.lastname@example.org, making it very easy to communicate your sentiment to them. An even better method is to pick up the phone and call. Now there's something to Yelp about!
Wine is a very personal experience. When posting about wine - talk about the types of wines you like (not the winery) and why you like them. Don't say, "there wasn't a single one I liked." That doesn't give much information to the reader. Instead say, "I like Sauvignon Blanc, but nothing came close to it." It would help to know what characteristics of the wine you didn't like. Saying they sucked doesn't mean anything to the reader, just to the writer. Remember wines change every year. I think this is what I enjoy most about the industry.
Take a look around the room.... are the servers (they are not waiters or hostesses) busy with a counter full of customers? Wine wasn't made in 24 hours, so give your server some room by letting them serve the customers at the counter and giving you the same undivided attention. Be patient.
As far as pricing... that varies from winery to winery. Ask why the high price. If the server doesn't know, maybe they can find out. There is a lot of pressure in the industry to keep the prices fairly the same. New barrels are very expensive, as is a new building, full staff, so look at the costs associated with that particular winery's crafting. I'm sure it is justified.
So as you head out this Spring, take good notes and report back, follow the rules and ask lots of questions.