Kelly Hopper has got it about right.
Netjets Europe does not exist. Netjets Ltd is a front for the setup.
Pilots are employed through Cayman Islands or Isle of Man, both of which are just holding companies.
Before you join Netjets it's worth a call to BALPA. Just ask them how many times they have been asked to intervene in the Netjets circus. Unsuccessfully, due to the arrangements of the company.
Not sure where or how the Lisbon groundstaff are employed. I'm sure Mike Jenvey THINKS he knows the answer