I have seen your venue and can I please assure you that you have made a brilliant choice. H2B and I went to Santorini last year and went to try wine-tasting at the Winery. Unfortunately the tastings weren't on because of a wedding that was held there on the 'outside bit' of the Winery. It was really gorgeous. The wedding was held at sunset and they had greek musicians that played the 'wedding music' (which I hope you're also getting). I also saw the restaurant part decorated and that was beautiful. One thing is that you don't have absolutely exclusive use (i.e. if you're getting married outside, there are tables on nearby part that non-guests can sit at to admire the sunset). However, we're getting married at Selene and we don't have the terrace actually closed off to the public (although it will only be us on the terrace)... if that makes any sense!!
Anyway, I hope I have put your mind at rest. Put it this way, I nearly cried when I watched the other wedding as it was so beautiful! The view is stunning and the place appears really classy. Hope my comments help!
ARe you going through a planner? If so, which one?