Even after Delta was fined for violation of the reimbursement limit guidelines, their web site still says this: “Reasonable expenses generally are $50 for the first 24hrs and $25 per day for the next 4 days the bag is delayed. The guidelines for reasonable expenses are NOT daily limits or a cap and additional expenses may be incurred and should be handled on an individual basis up to the limit of liability.”
Note that they apparently hope you will not bother claiming more, although the wording does leave higher reimbursements possible (which I guess makes the statement legal), but you still have to know to go after it.