Yes, this is flight training conducted under Part 91--nobody cares about whether or not you're holding out if he's seeking flight training.

On the other hand, if he's seeking air transportation (no interest in training), then you have to look at things like Ops Specs, Operator Certificates, drug testing, who has operational control, and will have to talk to someone much more versed than I on such subjects.

Intent here is a big deal too. If the FAA feels like you're attempting to game the system by logging training flights when that's not the underlying intent, you may be setting yourself up for trouble (particularly if your employer becomes a party to the transaction).