When it comes to wine there are different opinions from "experts" as to whether or not is should be served to the guest who brought it.If it's decorated that's usually an indicator that it's not meant to be opened that night and the particular event or dinner arrangements also can dictate whether or not it should be served at the time the wine was given.
What's interesting though, is that many people feel it should be served to the guest who brought it.I found this good advice at Cookinglight.com on Essential Wine Etiquette
When a dinner guest brings a bottle of wine as a gift, should you open and serve it?
Yes. Though there’s no way to be sure of your guest’s intention, wine is about communal sharing and fun. So unless the guest specifically requests that you keep and enjoy it later, serve it. Your guest will be pleased. And if you already had a wine you planned to serve, serve both. Tasting both wines will be an educational experience.