I rang DIBP 2 wks ago, the Officer told me I was booked on 9th March 2017 and the invitation letter will be sent accordingly 6 weeks before the ceremony. Yesterday I phoned Hurstville Council and asked if my name was included in the list. The nice lady said she hasn't received the list yet. If I hadn't phoned DIBP on the first week of January I probably wouldn't have gotten the slot of 9th March. Even the case officer was surprised when after going through the system I don't have the schedule yet. He asked me to phone again in a week as he will relay my case to the officer in-charge. After 2 follow ups I finally got the 9th March schedule. I found out recently that there's a long queue in NSW particularly at George River Council. When the two councils merged into one, waiting lists have doubled and the council seems to have overlooked this scenario as they stick to their original plan of having 6 ceremonies per year only.
I suggest to keep on calling DIBP after six months of waiting.