It is only your first licence you can lose if you get 6 points within 2 years. As you already have a car licence you wouldn't lose your bike entitlement if you did get 6 points.

The new drivers act can be viewed here new driver

"If you have held a full driving licence for two years, the Act doesn’t apply. For example, there isn’t another probation period if you already have a full car licence and pass a test in another category, like lorry (or bike)"