It’s not really a bond at all. They don’t make you sign anything.
Due to the lack of LTC’s and therefore a 2-3 months delay in line training; loads of freshly type rated FO’s have simply left with a TR & base training. Some to fly completely different A/C and there’s nothing the company can do about it.
An ex work colleague of mine has given up his flat in London and moved back to his parents for the last couple of months because he can’t afford the rent. (They only pay for HOTAC when you’re line training)