Couple of points if I may:
1. Given the strengths of the game in Aussie (league) and NZ (rugby), both codes can do pretty much whatever the hell they want with their local competitions - and invite teams from both countries to play, as they see fit. The NZRFU will be shit scared of the South Africans hooking up with Europe, there will be some heavy pressure going down on that one at present.
2. Big difference for football is we and Aussie are minnows, and we are in different confederations - AND we have FIFA laws around the make up of club leagues and player movements.
3. Whilst the idea of sending Phoenix youth players 'on loan' to Aussie NYL teams has some appeal, those teams have a player limits, ie they are set up to develop Aussie players and so only 2 import spots per team. Those spots usually go to African, Asian, South American or European kids who have not got Aussie citizenship. So unless the Phoenix youth players have Aussie passports, no chance; and even if they do (Alex Rufer i think?) there are hundreds of Aussie A league wannabes chasing the same spots, so it's tough. As to VPL/NSWPL clubs, they're only semi-pro and - in my opinion - generally don't have the set-up/environment that we'd want young players heading into.
Which leaves us with only 2 realistic options: sort something out with ASB/Youth for 14 weeks a year (shite option); or find the money and do the politics to gain entry into NYL as fully fledged Phoenix Youth.