It sounds like indentured labor.
Unless the company is spending huge amounts of money training you as in the airline industry, why would their be a bond period?
The notion of an employment bond for someone with 4–5 years experience is hard to fathom. Such a person, takes a risk by joining a company, they may end up working for an intolerable manager, in an inappropriate role, etc. and such a bond would enforce 1.5 years of such work.
In my opinion, it should be illegal to advertise in such a manner without an exceptionally good reason.