In the larger world this is known as "bonding". An employee either puts their
own cash up or buys an insurance policy. The cash bond or insurance policy
would be controlled by a third party (known as the bonding agent) who would
award it as a remedy in case of certain kinds of default on the employees
obligations.
You might see this a lot with security guards, locksmiths, and building
contractors who can all do substantial damage if they're unscrupulous or
incompetant.
But a bartender? And to protect against calling in sick? Run away screaming.
You do not need this job that badly. Bad employer. Bad situation. Yuck!