Q: iphone Keynote using mobile data

Hi

I have Keynote presentation on iPad and remote controlling the presentation from Keynote - iPhone.

As WiFi is not available I choose to use Bluetooth. Which is fine and does work

My Question is while using Bluetooth on the iPhone to connect to the iPad, WHY does Keynote on the iPhone want to always use MOBILE DATA to connect.

I thought Bluetooth worked between bluetooth devices as Apple instructions say.

As a comment it appears that the IOS 9x seams to want to use heaps of mobile data even for System Services (which you can't control)

If someone in Apple reads this… Let's bring it back to simplicity, easy to maintain and easy to use. Make it easy for the user to understand and control. You've been doing this for years, can you bring that back Please.

WI FI Assist???? oh please….

Thanks Great products… bring the intuitive ness back