Q: Iphone 6 can't find documents and data

Where exactly are you looking for it?

See how much storage you've used on your iPhone, iPad, and iPod touch

Ok, you're talking about icloud drive iCloud Drive FAQ

How do I access all my files in iCloud Drive?

You can access your files in iCloud Drive any of these ways:

• Using any supported web browser, you can go to iCloud Drive or iWork for iCloud beta at iCloud.com. In iWork for iCloud beta, you can find your Pages, Numbers, and Keynote files.
• On your Mac with OS X Yosemite, you can go to iCloud Drive in Finder.
• On your PC with Windows 7 or later and iCloud for Windows 4.0, you can go to iCloud Drive in File Explorer.
• On your iPhone, iPad, or iPod touch with iOS 8, you can access your files from Apple apps like Pages, Numbers, and Keynote, or any apps that support iCloud Drive.

I'm going to assume you already have icloud drive setup