Since somebody already posted it in /ttg/: https://i.imgur.com/gOmzSC1.png

I would definitely take this with a grain of salt without any further proof. First of all, there have been faked screenshots posted in the threads in the past, and secondly, Black hates Bonbi and loves to stir up more drama.
Could very well be that Black just goes off the screenshot that was posted here >>35, that supposedly shows Rhonda in Bonbi's house (without it being overly clear that it's the right house or the right peson). Or he is just parroting whatever crazy stuff the Russians came up with. And the fanfic somebody posted a few threads ago about the Blackbon stream being right before dinner with anonce (without any proof whatsoever either).
I wouldn't know where Black at this point would get any insider information from, so my assumption would be that it's not true.