The bonus doesn’t have wagering requirements and you can withdraw it immediately if you can grow it to minimum withdrawal amount which in my case I failed to rollover it on the minimum withdrawal amount.
It’s nice to receive this kind of bonus to try again bc.game original games.
Hmm it seems that you will get an email only if you are not visiting their website and not just an inactive player due to no bet for a week, I checked my email as per seeing this and I didn't receive any kind of email with the welcome back reward, even in my spams. If ever I will have this bonus too I will make a bet with this because its a free bet money so why not taking a small risk on this than taking a withdrawal just hope to try my luck in the game.