Why should you or your tenants be out of pocket?
Your issue is with your upstairs neighbour, not your tenants or even your owners corp.
Your upstairs neighbour should have home and contents insurance covering this incident. If not, they still have to pay (through a small claims court, if need be).
On the other hand, you should have landlord insurance (which is different from home and contents).
But, in short, your tenants should not have to pay any more or less than they would normally. But whoever caused the problem has to pay reasonable costs. Give your upstairs neignbour the hotel bill and suggest they contact their insurer.