As this thread has moved on a bit, heres my 10p's worth
IMHO, bonds are a good thing, far better in fact than the exploitative SSTR practice. However, there are some employers who will attempt to bond you on a non-reducing basis
i.e. you will be liable for the entire cost that the airline stipulates if you leave before the bond period expires.
IMHO this is unacceptable, a bond is a two-way agreement, it should reduce on the basis of length of service, and should recognize that as you become more experienced on type, you become more productive.
Another favourite bean-counter tactic is to inflate the size of the bond far beyond its actual cost, thats totally unacceptable.
Be wary, and be wise