I have a hot bin I purchased and I don’t put bones in. Having said that I did find a dead blackbird in the garden last year and as our grey bin wasn’t being emptied for over a week, I did chuck that in there. It disappeared and there was no trace of anything when I emptied the bin.
You might get away with cut up chicken bones, but I think lamb bones might be a bit of a stretch. Just my opinion, but the risk of injury from cutting up bones or stabbing your fingers on sharp splinters when using the compost outweighs any minor nutritional benefit they might add.