Read the fine print in your contract--you may need to prove how much you owe (ie, show them statements from your lenders), and it's possible your contract could say the loan repayment check can only be applied to specific eligible loans. I have never heard of the employer making a loan repayment check out to the employee's lender, but I suppose it's possible--not sure how that works out with taxes (if it's considered salary, you pay the taxes, if it's considered a gift, the giver/employer pays any taxes, if applicable)
Ultimately, any job willing to give you loan repayment should be willing to up your salary instead--it's all the same. The only difference is they usually limit how much repayment they'll give (ie., $20k/yr for 4 years). Everything in a contract is negotiable, and currently there's no tax benefit for you or your employer with how employer-provided loan repayment is treated, so it really is the exact same thing as a bonus. It gets taxed the same, and unless it's specifically stated in your contract, you could use those repayment checks for whatever you want.
