The latest e-Retail Sales Index from IMRG Capgemini also showed the back-to-back bank holidays almost doubled average alcohol order size against April 2010, to £174.
This was the largest basket value for alcohol since November 2007.
Brett Dawson, owner of Turton Wines, said: “While the number of customers rose, so did the average value and the number of bottles ordered.
“This meant a big surge in the online sales value with a 275% increase from April 2010.
“We put this down to the summery weather, with a large increase in white and rosé sales, but also to the royal wedding.
“Prosecco in particular was in big demand and so were Champagnes from the smaller houses rather than big-named brands.”
Overall, £5.2 billion was spent online in April, IMRG Capgemini said, a year-on-year increase of 19%.