Is it ok for a function or method not to be covered by a unit test? What situations?

Are there any situations where a function or method doesn't need to be covered by a unit test? What situations would they be or do they not exist?

For example I have the following function. It makes one call to another function, 'formatName' which is 100% covered by unit tests.

function SeatReservation(name, initialMeal) {
    self.formattedName = ko.computed(function () {
        return AH.Helpers.formatName(self.name);
    });
}

Is the above function a bit redundant because all it does is call another method but then again I want to keep as much of the logic in my viewmodel.

If I do need a test for the above is it ok to just check formatName has been called using a spy

ok(AH.Helpers.formatName.calledOnce);

Should getters be covered?