The other point to note is that this tanker (like the "LINDANGER) is methanol powered and can bunker at New Plymouth.

You are indeed correct, there is a large fleet of tankers that take methanol to China. I think all have called at Port Taranaki in the past. The methanol plants owned by Methanex are north of New Plymouth and is pumped to the Moturoa tank farm to await tankers.

Fleet at present is, CABO NEGRO II, CAJUN SUN, CARIBBEAN SPIRIT, FALKANGER, FINNANGER, GLOBAL SPIRIT,TAMIAT NAVIGATOR, TARANAKI SUN, TARANGER, WORLD NAVIGATOR, LEIKANGER, LINDANGER, MAGELLEN eNDEAVOUR, MANCHAN SUN, PATAGONIAN MYSTIC, SABREWING, SCARLET IBIS, MARI BOYLE & MARI JONE. Not all are methanol powered however.

It's the logo of Waterfront Shipping Co Ltd, Vancouver, the shipping subsidiary of methanol producer Methanex:
https://www.wfs-cl.com/

Why the dual funnel colours ? (Top Westfahl-Larsen and bottom blue and an arrow ?)