Data sharing with a hub?

I am trying to figure out family plans, data sharing across devices, and mobility plans.

We have 2 phones with another carrier, neither of us use much data, probably less than 3 G per month combined.

We have a Telus landline.

We have a Telus Hub on a 500GF plan.

We cannot get Telus tv.

I am thinking about getting a new Iphone and cannot find information that I need before making that leap, so here are my question/s:

Is it possible to bring both cell phone plans back to telus and share the data we are paying for on our Hub 500 plan with our cell phones? I seems silly to be paying for 3 different data plans if we don't have to, and I see one now called 500 GB w'sharable data.

I'd switch the landline too but we need it in case of a power failure, so I don't think switching that to an internet line would be a good idea? 

Advice would be greatly appreciated!!