I contacted Aegean via the web portal. I asked if they could match my current Silver status from Miles and more to Miles and Bonus. I received a reply teh next day with a negative answer.
Dear Mr. XXX,
We have received your message and we would like to thank you for contacting us.
After having reviewed your claim, we would like to inform you that the Miles balance or your Miles+Bonus status cannot be transferred to any respective frequent flyer program's cardholder in any other Star Alliance member-airline and vice versa.
We remain at your disposal, for any future assistance.
on April 22, 2019