I have had clients where the wine they serve is more important to them than the reception dinner itself. Because I am a cheap drunk (like tipsy from one wine tasting,) I found myself at a lost when providing them advice on the amount of wine that should be served at their wedding. Sure they knew what wines they wanted but they didn't know how much wine to buy or budget for. As their wedding planner, of course, I had to do my best to estimate and help them stay within budget.
To start, we need to know roughly how many guests are attending the wedding. Then, I had to ask the age ranges of said guests. (If there are a ton of kids, likely the kids cannot drink and the parents will not drink.) After you have a rough idea of these two things you can start estimating. (Refer to infographic below.)
One rule you must follow is to NOT RUN OUT OF WINE. This will be a huge downer for you and your guests. (If you are buying your own wine, ask about return policies. Some stores allow you to return unopened bottles of wine.
Infographic Credit: The Knot