Samsung Galaxy S5 Active — Sharing an Internet connection

I own two android phones. One is a Galaxy A5 I use as my primary phone for calls and the web. The other is a Galaxy J7 I keep in my car with pay as you go service. I can save money on my car insurance if I accept a driver monitor Seems like I would have to provide web access to the Galaxy J7 for the Insurance Company monitor. Providing web access using the T-Mobil phone in my car would be expensive. Wondering if I can somehow utilize my web connect with AT&T Galaxy A5 without having to add an extra line. Blue tooth looked at a possibility until I realized the limited range of the A7 would not work as I drive the car far from home. Paying for an additional phone line would nullify the advantage of the car discount. Any work arounds for this problem?