An iPhone must be jailbreaked (and an Android rooted) in order for a VPN to be shared directly as a Hot Spot. Most VPN apps allow you to use your account to login from 5-10 separate devices. For a team of co-workers at a remote location the VPN can be installed on a router.
If a VPN app is set to perform zero-logging the provider will not access your data. But keep in mind that some services like Google and Facebook will log your activity even if you are using a VPN.