I am a Philipppine passport holder, I have visas for both countries Australia & New Zealand. Planning to travel for my birthday. I want to fly directly from Manila to Sydney, spend 1 week in Sydney then fly to Auckland directly from Sydney and spend at least 1 week. Then fly back again to Sydney and fly to Manila. As long as I have the required visas for both countries I can enter without any problem with the immigration right?
Well, yes. There's Philippine Airlines and Cebu Pacific and others that fly direct from Manila to Sydney.
Then there are several airlines that fly to Auckland and back (Qantas, LATAM, Virgin, Air New Zealand, Jetstar and more).
So for the cheapest ticket, you'll perhaps want to consider booking a return ticket to Sydney, and a return ticket from Sydney to Auckland.