I'm not sure if I'm reading the original post correctly, Ritesh. Am I right in thinking that you're already here on WHM, and want to bring your wife here after the wedding, so that you can be together until it's time for you to leave?
If that is the case, then it is true that there are no formal arrangements for dependents on the working holidaymaker scheme. But if your future wife is also a Commonwealth citizen of the right age, I can't see why she can't make a WHM application for herself, and simply leave UK early, when your own time for departure comes round.
The WHM guidance on the UKVisas website talks about coming for "up to two years" which implies that shorter working holidays are permissible. Perhaps it might be worhtwhile making enquiries at the visa-issuing office in your home country, making it clear (in case they might have doubts) that your wife would be returning home at the same time as you.