As I understand it, the Vitality status matters little from 2024 onwards since everyone gets a flat rate of 10% off flights, upped to 25% if a health check is done and all indicators are in-range. The only way it does matter is if you're an Invest or Life Insurance client.
On top of that, the only way to then increase your flight discount is by being a Bank client. Of course, there's only one way to access your flight discounts: you have to be a Bank client to "access" Vitality Travel. This, says Discovery, is easy enough because all you have to do is sign up for a zero-free Discovery account with Bank. But there's not much point to signing up for that account because, as I understand it, even if you want to use your flight discount through Vitality Travel, you can only pay for a flight using some kind of Discovery credit card.
In short, to use your flight discount, you have to be a Bank client. And for this reason alone, Discovery can get f*cked.