This is just from a light research, so please correct if there are better links, but https://internationaloffice.berkeley.edu/h-1b_faqs#1

> The H 1B also requires that the H-1B employer pay the H-1B employee the prevailing wage or the actual wage, whichever is higher.

And https://www.dol.gov/whd/h1bworkers.htm

> and you must be offered fringe benefits on the same basis as offered to U.S. employees.

But now that I read it again, they may be separate things that don't sum up. Is that what you meant?

Right. I understand that as "H-1B holders can't be offered an inferior health plan/401k plan/commuter benefits/bonus plan/FSA than US employees". But none of those things count toward the prevailing wage calculation. Only base pay is considered when determining whether the employee is paid more than prevailing wage.