The short answer is no. I have never heard of this being done, although some of our fleets (and a few Citation Xs) do have jumpseats. You would have to be a guest of the owner, it would never be done as a guest of NetJets. The only people on board owner flights are the owner(s) and the crew....my company is thinking of signing on with NetJets.
...any chance they'll let me ride jump seat sometime?
If it's your damn plane you can elect to pay for your type rating and fly up there yourself.
Somebody's thinking. It's me.