What is a jetpack? Is it a mobile hotspot? And if so, two devices connected to it and talking to each other count against your data plan? That doesn't seem right, given that neither of the devices are actually talking to the telco's system.
If you do not have access to wifi at home then I would consider a wifi dongle like this one:
http://www.amazon.com/ASUS-Multi-Mod.../dp/B00CWIRMRC. I have one and use it at hotels, airports, etc to connect my "stuff" together.