iphone tethering to time capsule

Hi, new poster here but I have a question regarding my new setup at home.
It's my second foray into the mac world after a couple of years away so I am familiar with Apple hardware and OS.

I have recently purchased a macbook pro and time capsule after being impressed with my Iphone. The macbook has replaced my old laptop. I have an xbox and my girlfriends and mine work laptops (windos 7) too. I may also buy an apple tv. Dependant on the answer to this question.
My girlfriend and I both use 3g connections for internet access. I use my iphone and she has a 3g usb.

So i setup the time capsule last night via airport utility
My idea was to have the time capsule as a media hub for movies, pictures and music and incremental backups for my macbook and my girlfriends data, I also wanted to extend my iphones wireless sharing with the other network devices using the time capsule since I do not have a adsl connection into the house. However, when I came to the option for doing this, I couldn't see the iphone in the networks presented which is pretty **** annoying.

Is there some restriction from apple that prevents this?
Is it possible that I couldn't do this because I may have set the band on the time capsule to 5Ghz (I only just thought of this, but i am sat at work so can't check it out)

It would be quite annoying if US carrier restrictions enforced on apple mean I can't use my phones internet (I get 20Gig data a month) as my connection, particularly since I am in Denmark. And last night when performing my first time machine backup, it became apparent that I couldn't use the phone connected via USB to my macbook whilst being connected to the time machine network.

Does anyone have any ideas?


Thanks

First of all I assume you are running the latest version of IOS 5, which has Personal HotSpot as an Option.
I believe sharing your internet connection via USB is intended to be by hookup to your Mac, not to your TimeCapsule.
A better option maybe to use the Wifi link (again not sure about the TimeCapsule in this) I haven't tried this yet since my iPhone 3Gs will only connect via Bluetooth.
I did some followup research and from what I can see you can't do what you want to do. You can point to point share (by individual device to your iPhone) but you can't set up for general access via TimeCapsule.

EDIT: Added link to Apple Support Document on Personal HotSpot
http://support.apple.com/kb/HT4517

I should have clarified, the connection via USB was to my macbook pro after I setup the time capsule. Because the airport utility wouldn't see my iPhone wireless network to extend it.

I am fully upto date with patches on all devices and the phone is a 4s.
Seeing that I was unable to extend the iPhones wireless via the time capsule was when I connected it to my MacBook pro for an Internet connection whilst I moved some data onto the TC. The Internet connection via USB wouldn't work whilst connected to the TC WLAN .

This is from the link I posted

"You cannot use your Wi-Fi connection for Internet connectivity while other devices are using Wi-Fi for Personal Hotspot. You can share only a cellular data connection; you cannot share a Wi-Fi connection."

Which rules out sharing the connection over the TimeCapsule. Not sure, though, why the USB connection should have dropped out simply because you were connected to your TimeCapsule thru wifi.

Hmmmm this may have been it can't be sure however. It is possible that the was connected to the MacBook pro when I set up the tc (since I needed to download some updates beforehand). Will check and report back.thanks.

Ps sorry for not checking your link, I am on the bus on my phone.