Don't know about EY, but for EK its 90% discount and you go standby or 50% and you are guaranteed a seat (well almost anyway). Apparently if you are a low grade staff booked on the 50% there is a chance they could bump you for revenue.
And AFAIK this extends to all first blood family members and their respective spouses/children but no to friends.
And no lounge access (which seems a bit mean to me).