Thanks for bringing this up! I was wondering, and I know that I've seen and replied to a thread before that is pertaining to 1win, until you mentioned it here.
There has been lots of complaints to this casino, they cannot withdraw, and it seems like their voucher or any of their bonuses are just a "front" to attract possible users.
I never visited the site until today, it was really built good, in fact it was a beauty. Only that there are lots of scam accusations against them.