If it is at all possible it would be done this way...
1. Go into "Settings" and in the "Wireless & networks" section tap "More".
2. Now tap "Tethering & portable hotspot".
3. For "Wireless Tethering" tap "Set up WiFi hotspot"
4. On this new screen you will see options for a "Network Name", "Security", "Password" and "Network Band". You can change them or keep them as is. It is really up to you.
5. Now you would just need to search for the hotspot by name using the second device. (the TV)
NOTE: While a WiFi hotspot feature is built into Android, some service providers/carriers, especially in the United States, hide it. You would then need to see if you can locate an app that you can install to help with this.
Also, carriers/service providers can limit the data your device uses. Even if you have unlimited, the data speed can go down. And not all devices can connect to a phone using its data for a hotspot. If you are, however, connecting to WiFi through the phone (and not using the phone's data) then that isn't using the phone as a hotspot and you would just need to connect the TV directly to the WiFi. No phone involved.