What is the name of a wine bottle holding equivalent twelve bottles?

There isn't a specific name for a bottle that holds the equivalent of twelve regular wine bottles. However, you could refer to it as:

* A case of wine: This is the most common term, as a standard case usually contains 12 bottles.

* A twelve-pack: This is more common for other beverages, but it could be used to describe a box containing 12 bottles of wine.

* A magnum: This is a bottle size that holds 1.5 liters, equivalent to two standard bottles. You'd need eight magnums to hold the equivalent of twelve bottles.

It's important to note that the term "equivalent" is used because some wine bottles come in sizes larger than a standard 750 ml bottle. For example, a Jeroboam holds 3 liters (four standard bottles).