Bonding is a real mine field these days but providing the bond is reasonable then there should not be a problem. In a previous company one of our pilots had a brother who was an employment lawyer. His take on this was;
A company could bond you for, as long as and for how much as they liked but once the bond was complete then you could no longer be re bonded for up grades or second or subsequent types on your license; as this was prejudicial to promotion, which is against employment law, as everyone should have equal opportunities and re-bonding was a detriment in this regard.
That particular company was trying to re-bond for conversions on to second types.
BR.