Just found this thread (thanks @jensrichard77).
I have also been contacted by Bonsaï Éditions and are currently in dialogue with them, and this is my experience so far:
I have gotten a draft of a contract that seems very promising, however I (read a friend of mine on the paranoid side of causious) found inconsistencies in the spelling of the website.
In the message I recieved here on Tapas they wrote bonsai-editions.com, but in the contract it was spelled bonsaieditions.com. When I contacted them about it they said it was a typo, and that the first is the correct spelling, and that seems plausible to me.
The hyphenated domain has been bought as they state they have, the un-hyphenated is not.
Their mailing adress is also "bonzai" and they use a hotmail, and when confronted with that they told me "bonsai" was already taken which I find plausible as it is a very commonly used word in nerdy circles. I would prefer however if they had a mail adress linked to their site, aka mail@bonsai-editions.com or similar.
I have not been able to find anything on the person contacting me either online, nor the username here on Tapas, which is still sus to me.
I asked them for screenshots/proof of their work on the website, and I did get a screenshot of a Bonsai Editions front page, and images of their little bonsai mascot for promotion purposes.
My gut feeling is promising with these guys, the contract doesnt have any fine print traps detected by me or my paranoid freind, it specificly states the country of operation and which country's copyright laws applies (France if anyone cares).
I'm still vetting them, but so far I've been satisfied with their answers. I know I'm quite gullible however, so I am collecting opinions from more sources. I have yet to contact the Danish Union for Comic Creators as I am a member of and ask for their opinion, but I have plans of doing that this coming week.
I'll let you know my further progress.