you would need to be on the same wifi network, and the devices would need to see each other, which may not happen in a hotel, it could be set up so you don't see everyone's computer in the hotel.
Your aTV will also need to be signed into your iTunes account for home sharing, without this the remote app on the phone won't work.
and without a remote, there is no way to sign into home sharing, so you would have to already be signed in.
it might be easier to get a new remote, either an apple one from the apple store, or most universal remotes come with the apple codes in them, should be able to pick one of those up anywhere that sells electronics.