Hey, uhh, can the Bonus Edition be bought anywhere else than Steam? Thanks to my fucked up government a 35 years old male has to be protected from every visible nipple (in other words any H game is sadly blocked on Steam).
Not at the moment, though the game is available as part of a subscription on SubscribeStar. I'm looking into submitting the game to GOG.com for review. In that case it should be available in your country. As soon as the game is approved, I'll notify people here as well.
I think you need to obtain an official classification from the USK which will certainly give it an 18+ rating. I believe German law then requires storefronts to take additional measures to sell that adult content and Steam doesn't want to comply with those rules. Some additional context can be found here.