OS X El Capitan Continuity

Hello,

I am using the following:

I have searched diligently and can't seem to find an answer to my specific issue. I see the Handoff icon appear in the dock of my MacBook Air (for example, when I open Messages on my iPhone 6 Plus (Space Grey, 64GB)), and it is my understanding that Handoff will allow me to START typing a text message on my iPhone (i.e, I begin a text to my wife and have typed the following: "Hey, how is your") and I can click the Handoff dock icon on the MacBook and it will open the message to her and display what I had already typed on my iPhone, "Hey, how is your" and I can type the rest on my MacBook, "day going?" and send it.

The reason I ask is because I know that using an Apple app like Numbers (which is iCloud-based), and if I'm editing a document on my iPad and open Numbers on the MacBook, it will give me a pop-up saying:

I would just like to know if this is truly an issue with my devices, or if Handoff doesn't actually function in this way?