Max MB/s of the iPhone hotspot?

When you click "Maximize Compatibility" it uses 2.4GHz band and if you uncheck it, it will use 5GHz band.

Theorethical speeds are:

2.4 GHz = up to 600Mbps - more interference - less channels - bigger range coverage

5.0 GHz = up to 1,300Mbps - less interference - more channels - small range coverage

** real life value may differ, but alot of interference for 2.4GHz, might as well go for 5 if your devices support it

Hello JJkon, 

It sounds as though you’re wondering what data speeds are supported by Personal Hotspot on your iPhone. Apple Support Communities is a great place for help! The data speeds may vary as it is based on your carriers network, and the how many service bars are currently on your device at the time of using Personal Hotspot. 

Reaching out to your carrier/wireless provider would be the best route for the most accurate information regarding their data speeds.

Take care!

Interesting, but irrelevant. The OP is asking about the cellular network speed when using the personal hotspot on the phone. Cellular network will be the limiting factor, not the Wi-Fi speed.