Is amphibians being descended from fish reflected in the animalia taxonomy?
Fish are a paraphyletic group: that is, any clade containing all fish also contains the tetrapods, which are not fish. For this reason, groups such as the class Pisces seen in older reference works are no longer used in formal classifications.

You got something completely wrong. In evolution one can not say that one taxonomical group evolved from the other. We say that two taxonomical groups have common distant relative. With that said all vertebrates have common distant relatives. Important is to know when did the branching in speciation happened.
Proto-amphibians evolved in Devonian by further speciation from relative that was sarcopterygiian (fish). It was a fish with some properties of amphibians (lungs and bones in appendages).