HI Joss & Rob Lovely plant looking well established & I suspect that it is a naturally occuring plant and if so it is probably Dracophyllum latifolium, which is the broad leaf Dracophyllum occuring in the Waitakeres. It does overlap in some areas with D.traversii but generally only in montane areas. Diagnostic features from the foliage are leaf width less than 3cm and teeth _5 per cm = D latifolium. Leaf width 4+ cm and teeth 10-20 per cm = D. traversii.