Pairing two iPhones via Bluetooth
I'd like to transfer just the Contacts from an iPhone 6 to an iPhone 6S (both running IOS 9.1). Need to understand how to pair these tow phones via Bluetooth.
iPhone 6, iOS 9.1
You don't. iPhones cannot pair to each other over Bluetooth.
To transfer contacts you can use iCloud, or iTunes.
Transfer content from an iPhone, iPad, or iPod touch to a new device - Apple Support