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AFAIK for UA Mileage Plus (as with most star alliance frequent flyer programs), only *A airlines count for EQMs. So a *A codeshare on a non-*A operated flight will not earn EQMs, but might earn RDMs (likely if you are on a UA codeshare, unlikely if you are on another *A airline codeshare).

DJ Virgin Blue has UA codeshares on selected flights (eg Sydney to Brisbane), for which you can earn and redeem on. However, to get ticketed under the codeshare it must be on part of an itinerary that includes UA trans-pac. So for example you cannot book DJ SYD-BNE-SYD under UA code unless your ticket is something like LAX-SYD-BNE-SYD-LAX.

There is no *A intra-Australia, however flying to other countries there is Air NZ (Asia, USA and South Pacific islands), Singapore Airlines (via Singapore), Thai (via Bangkok), Air China (via Beijing), Asiana (via Seoul), United, Air Canada (via Vancouver), South African (via Johannesburg).