The RTWMC can be used to email your itinerary to *A RTWMC headquarters, which then in theory passes it on to the airline you selected from the dropdown list. My choice was Air NZ. The email went out successfully and I received a booking reference number and the itinerary was emailed to my own email address. However, so far (1 day later) nobody from *A or from Air NZ has contacted me.

Does this centralised automated system actually work in practice, or should I simply contact Air NZ or my TA directly ?

Edited to add: Now I see that the email sent to me says "Please print your itinerary or this email and take or send it to your travel agent." So I guess the automated aspect is not working.