Interesting. But Im sceptical. Long-tailed bats are the species most likely to be in a suburban environment, they are known from some cities (eg Wellington, Hamilton) and will utilise patchy forest environments.
However long-tailed bats are well known to be quite passive. Even when they are caught and handled they seldom bite and surely this would be percieved as a far greater threat than a person quietly watching from the ground?
A confirmed observation of bats in Rotorua would certainly be a valuable observation.