Hi Bryony,
As a Property Mgr a few years back in Melbourne, my experience with Landlords and renters with pets were they really did not like having dogs or cats as pets kept in the house...We would often have tenants say while applying for a lease "the dogs were 'outside' dogs", only to have carpets etc damaged in a very short time by the dogs.
If you feel a need to advise the Real estate people you have reptiles, it would be good if you could tell them you have reptiles that are kept in locked, secure enclosures, just so the LL does not imagine them running/slithering about the house etc etc. They will also see reptiles cannot damage property, as a cat or dog can.
Often they are more concerned with the breeding of rodents to feed the snakes.
Good luck, Judy