They are half sparkling wine, half orange juice so each glass is half wine. Not exactly a powerful drink.
At Spirit of Aloha, the waitress was quick to serve the first beer. After that, it was all I could do to flag her down and order another since runners brought out the food. It took quite a long time after I ordered them to receive my two refills.
On purpose or not, three seems to be the maximum number of "bottomless" drinks at Disney.