Usually, the term being used for this is rakeback by casinos. But check the percentage as it varies from one casino to another as well as it depends on how much you wagered on their site. You may be looking forward to this rakeback at the end of your session, but you may get disappointed as most have low percentage vs. your wagered amount. But this feature is already good as compared to none. At least get something from your wagered amount at the end of the session.
Loss bonus seems to be cashback which is something based on how much we lost, so it is different to rakeback which is based on wager.
I myself prefer rakeback than cashback or whatever it is called by the casino (loss bonus or maybe loss back).
Rakeback usually can be claimed instantly as we wish while cashback is usually being sent once a month because usually cashback is calculated at the end of the month by looking at our whole profit.