I'm concerned about you purchasing these tickets with your own credit card. The least expensive tickets are non-refundable. What if you book something and he has to re-schedule? The University is certainly not going to reimburse you for a trip that he did not take. You could lose the amount you paid for the ticket, which could be hundreds of dollars. Some Universities do not reimburse until after the trip has taken place. So, you could potentially purchase a ticket in January for March and not be reimbursed until April.

Also, the University's Accounting department will expect the receipts to be in his name, not yours. I think you will have trouble getting reimbursed. I would talk to the Accounting Department about this process before going forward. They will have a lot of arcane rules that will make the payment (or repayment) process slow and painful.

I think that Ghadji1 has the right idea of booking travel for bands or other small entities without the bureaucracy that will come with a University. And I would not use my own credit card for someone else under these circumstances.