Yes and no.
If you get a SIM card for it, it will be a separate data plan of a certain number of GB (there's no unlimited for Mobile Broadband devices)
However, if you get a WiFi version of it, you can tether it to your SII. The caveat is you're limited to the amount of tethering based on your plan. The grandfathered plans offer no tethering options for the Unlimited. The Simple Choice Unlimited offers 500MB tethering. If you need more, you'll have to be on one of the GB plans (I think they're increments of 2GB for $10, starting with the $50 being 500MB unlimited talk text, then $60 would be 2.5GB, 70 would be 4.5gb (also the same price as unlimited), 80 for 6.5gb, etc)