Thanks - have you tried it out yet? As far as I understand, the only previous hotspot option with VM was buying a $5 "day pass" and then jumping through some hoops to get it to show up under Settings -> Cellular.
Oh - yes, I'm in the US, and the plan in question is their $35/mo. "Unlimited Your Way" plan. My mileage may differ, as they say. Did you have Personal Hotspot prior to 8.1 under Settings -> Cellular?