As far as I can recall, the licenses don't cross over to different platforms. I don't believe that Mac uses e-license, it's got a different scheme. Sorry to be the bearer of bad news!
I suppose you can talk to Marc Duffy (
marc.duffy@sigames.com ) and see what he has to say, although I can't right now think of any other game bigger than solitaire where if you buy it for a PC you'd get to use it for a Mac for free.