"How are you, Peter?"
Translation:Hogy vagy, Péter?
it isn't, usually you would only include 'te' if you wanted to emphasise the object, for example in the following conversation: -Hogy vagy, Kati? (How are you Kate?) -Jól, köszönöm. (Fine, thanks.) -És te hogy vagy, Péter? (And how are YOU, Peter?)
No, the two sentences are not really equal, I would translate "Te hogy vagy, Péter?" such as "As for you, Péter, how are you?".
"Te" is the familiar form of "you". It is not necessary here, since it is understood.