I'd make sure that your iPhone is up to date by plugging it into iTunes, and checking it that way.
Also if you have the Share Everything plan that enables you to have a free hotspot, or if you have a seperate paid feature.
Phone is up to date and I have the shared everything plan. Also have an android phone on my acct. that I use as a hotspot and there wasn't a need for a separate paid feature on that one. Hmm
No, your android phone would not need an extra plan to use as hotspot either if it is on your Share Everything account. Hotspot is included on that phone too. I use android phones, but I played with an iPhone at Sams Club and enabled the hotspot and bluetooth and USB tethering too it was very easy. I just cant remember the steps now, i'd itemize them if I could. But I do recall it was under the General menu somewhere.