> The municipal water supply in Suva, Nadi and other large towns is chlorinated and can usually be trusted, but elsewhere avoid untreated tap water.

This is true everywhere in the world, is it not? What are you judging if not the municipal water supply?

This is sourced from Lonelyplanet and to my judgment this means tap water is drinkable in larger towns, while it's not in smaller towns in general.

This is not the same across the world, in countries like Switzerland, for example, you can drink the tap water virtually anywhere, while in some African countries this is not even true for the capital cities.