iPhone Tethering plan: how does the 2GB "allowance" work?

I just signed up AT&T 5GB data plan, with includes Wifi tethering. One thing I am confused about is the "2GB allowance" for tethering. I know that the second highest tier is 3GB, which does not include tethering. So, my question is, when they talk about "2GB allowance", does this mean I am only allowed to "tether" 2GB worth of data (and thus once I've used 2GB via tethering, I won't be able to tether any data again until the next month, although I will still be able to use the rest of the 3GB on the iPhone, or, if I wanted, could I tether all 5GB worth my available data if I never use any data on the iPhone alone?

Thanks for any help,
James

Edit: okay

I'll have to look into this, as I have the 5GB Tethering Plan and am not aware of any 2GB allowance.

EDIT: I could not find any reference to a 2GB allowance. As far as I know, the 5GB can be divided between iPhone, iPad or any other tethered device however you wish.

Bump does anyone have any idea? If my question is not clear, here it is paraphrased:

With the AT&T 5GB Data Pro plan, and I only allowed to use 2GB of the 5GB for tethering, or could I use more if wanted?

Thanks for any help

EDIT: I posted before reading Razormac's edit, thank you Razormac I believe you are right.