According to Trade Data and Analysis, the 932 residents of Vatican City consumed more than 70 liters (18.5 gallons) of wine per capita in 2009, followed by Luxembourg, whose 500,000 residents drank 54 liters (14.3 gallons) per capita.
Granted, the low populations of these countries push those ratios higher. And it's fair to say that no children live within the borders of Vatican City. But there are smaller countries such as Andorra and the Cayman Islands who come in lower on that list.
So what's the deal? Remember that the sacramental wine is a cornerstone of ceremony in the Catholic Church. With that in mind, if Vatican City ever dropped out of first place, that would be the bigger story.