"Additional benefits" refers to extra advantages or perks that come along with something. It could be something extra that you receive, such as additional services or features, that go beyond the basic or expected benefits. Full definition
However, there was little evidence of additional benefit of group therapy when added to routine care. (ebmh.bmj.com)
By signing up to this free program, you get access to a range of additional benefits for flying with them as well as the ability to earn points and redeem awards. (upgradedpoints.com)
It also provides additional benefit of a life cover and free accident insurance cover. (myinvestmentideas.com)