If you think about it, there are hundreds of thousands of combinations of wine labels and vintages from thousands of producers. Some people who collect the wine and store it at home will want to enjoy the wine they have with a professionally prepared meal, and will bring that wine to a restaurant, and enjoy the entire service aspect of it (pouring into nice glasses, etc.).

It doesn’t make much sense for ordinary bottles of wine. So the people who do this usually bring special, hard to find, significantly aged, or sentimental bottles. And because the restaurant still provides the service of opening and pouring the wine into nice glasses that they’ll clean, there’s usually a per bottle charge added to the bill.

So it’s not super common, just also not super rare, either.