They do not advertise the next level, it is by invitation only and not one I ever expect to reach. A similar situation occurs within American Express.
They used to have Gold as their top card and then found they had lots of people there. So they started Platinum and then had lots of people there, they had a big incentive to invite people up to Plat as they get charged more money! So the real top card is Centurion (after their logo) but it is invitation only and be sure to have a long standing membership and a very considerable amount of money.
So there is usually one more step, why not phone VS Gold helpline and 'play innocent' by asking what incentive you have to stay with them during your current membership year.