It doesn’t matter who Peter was preaching to, the miracle happened. The age of miracles is NOT past and the bible does not anywhere tell us that the age of miracles is past, other than your personal interpretation that is not infallible.
What I'm trying to make you see is that healings, miracles, signs, wonders, dreams, visions, etc. were the operating norm as long as God was dealing with Israel. When she became Lo Ammi (not my people) in Acts 28, those practices stopped. NOW, we walk by FAITH, NOT by SIGHT. And will until He resumes His relationship with Israel (Tribulation). THEN all of those things Peter and the 11 were doing will once again be performed. Why? BECAUSE OF ISRAEL. (The Jews require a sign).