I always found with DD that if I couldn't get wind up it just went down and that was where we had problems. She then struggled to move it and was uncomfortable.
In the UK Infacol comes in the form of drops, so you just fill the dropper with the stuff and give it before the feed (as I recall). No idea how it comes in NZ, though
DS's paed (for his reflux) wasn't keen on using it and described it as "harsh". I really feel it exacerbated reflux symptoms in DS as the gas bubbles in his tummy got so big that they then pushed up his milk
As for gassy foods, some people certainly do find that some foods seem to have an affect on LO, but there's also the suggestion that a reduction in "gassy" foods will simply reduce the amount of wind mum has rather than baby as there's little hard evidence that anything in those foods that causes wind can cross into the blood/milk in order to give issues.