From the iPhone / iOS perspective, USB tethering only works in one direction - internet service can flow out of the device but not in to the device.
A cellular data device is capable of turning on tethering whereby it will serve as a router for one device that connects over USB. Even though Mac OS will offer to do the same, iOS will not listen for an active Internet connection over USB and only will tether to a computer over Wi-Fi.
On a technical level, USB is an asymmetrical protocol with one host that communicates to all downstream endpoints. Just like you can connect a USB hard drive to a computer but not reverse that flow and get the hard drive to act as the host and the computer to act as the drive (even though many hard drives now have computers in them and your computer could work as a hard drive and just store data - this is exactly how Target Disk mode sharing works over Firewire and Thunderbolt and other symmetrical protocols like ethernet, Wi-Fi and potentially Bluetooth).
Practically - your Mac will tether to an iPhone/iPad and can receive internet service over USB, Wi-Fi or Bluetooth. In the reverse direction for the software you list, only Wi-Fi is viable for the Mac to share it's internet to the iPhone (or iOS device).