This repayment is not tax deductable.
A "Bond" is not a benfit in kind and is therefore not liable to tax. The only exception might be if the employer chose to pay it for you in which case it may well be.
Having to repay a bond is a financial penalty that you volunteered to at onset. It is a penalty you agree to pay it is not an expense any more than breaking the terms of a fixed rate mortgage would be. Neither of these constitute allowable expenses.
Speaking as an ex-taxman!
