Sharing iPhone WiFi connection
There are Three Methods to Share internet from iPhone to other devices as per my knowledge.

Method 1 : Via Hotspot


On your iPhone tap the Settings app. This may be located in a folder labeled "Utilities."
Tap the Cellular option.
Toggle Cellular Data ON if it isn't. This will need to be enabled in order to turn on the wireless hotspot.
Tap Set Up Personal Hotspot 


  This button only appears if you've never used the personal hotspot before.
  
  After setting up your personal hotspot for the first time, the Personal Hotspot option will appear in the main Settings list.

Click the Networks button in Windows. You'll see this in the System Tray in the lower-right corner of the screen.
Turn on Wi-fi and Connect to the network displayed with the password shown on iPhone.


Method 2 : Via USB Tethering


Install iTunes on your computer. 


  If you're tethering your iPhone to a Windows computer, the computer will need to have iTunes installed in order to connect.

Tap the Settings app on your iPhone. You can find this on one of your Home screens, or in the Utilities folder.
Tap the Cellular option.
Toggle Cellular Data on. You'll need this enabled in order to share your iPhone's internet with your computer.
Tap Set Up Personal Hotspot option.
Plug your iPhone into your computer's USB port.


  you will see a prompt how to share the internet ( over USB only or wifi and bluetooth as well )

Click the Network button on your computer. In Windows, you'll find this in the System Tray.
You can now setup iPhone as a new network.


  Click your iPhone to select it as your computer's network. Your computer will now use your iPhone's internet connection as you browse the internet.



Method 3 : Via Bluetooth


Follow same steps till turning on Hotspot
go back to settings menu
Toggle Bluetooth
on Windows: Click the Bluetooth button in your System Tray. If you don't have a Bluetooth icon, your Windows computer may not have a Bluetooth adapter installed.
Click "Join a Personal Area Network."
Click the "Add a device" button. This can be found at the top of the window.
Click your iPhone.


  Don't Close this Window.

Tap Pair on your iPhone. You may be prompted to enter a code that is displayed on the other device.
Return to the Devices and Printers window.
Right-click on your iPhone.
Highlight "Connect using" and then click "Access point." Your Windows PC will now use your iPhone's internet connection over Bluetooth.