iPhone 6 plus iOS 9/Mac (Yosemite & El Capitan) unable to communicate via Airdrop nor USB connection

Airdrop: The Macs can see each other; they cannot see the iPhone nor can the phone see them.

USB: Neither recognizes the iPhone as a device when connected.

TROUBLESHOOTING TO DATE:

• iPhone
  • Restarted iPhone
  • Reset iPhone Networking Preferences
  • Ensured that both Bluetooth and Wifi were connected
• El Capitan
  • Deleted Bluetooth preferences
  • Upgraded to the most recent OS
  • Tried additional USB connector
• Yosemite
  • Restarted
  • (not my machine - no real access to troubleshoot)

iPhone 6 Plus - iOS 9.2.1

Mac Book Pro - [late 2009] Yosemite + [late 2011] El Capitan 10.11.3 (15D21)