with the latest update for Keynote, clear to iOS 7 + +, this pairing between iPad and iPhone is still easier to make several versions ago, and is also done with either WiFi or Bluetooth.
I have several years using this form (iPad / iPhone Keynote >> / Remote) and works great. Even gave a lecture, paired by BT, where the iPad was in a projection room about 30 feet from my iiPhone and everything worked perfectly; I observed no delays in transmittance
System emo highly recommended: - 3