Holiday Visa Wiki
It's always a pain searching embassy sites trying to find out what visa you need…
With Aegan’s change to their loyalty program you will need to check their specific fares that are eligible for mileage accrual to keep your current class.
You can use this link to find the class : http://travelisfree.com/2014/09/15/how-to-find-the-fare-basis-code/
You can then cross reference this against : https://en.aegeanair.com/