A colleague and I both are finding we cannot access Sony services (Music Unlimited, Playstation app) while on 2Degrees 3G/4G network. The apps work fine when attached to home or work wifi. I'm using an S5 on 2Degrees and S4 on Spark and the same apps work fine on the S4, and work fine when I put the Spark SIM into the S5.
To recreate the problem, use the Android Sony Music Unlimited, Playstation app or a Vita tethered via Wifi to try to login to your PSN account. The login will always fail. I think the api and/or account.sonyentertainment.com sites are being blocked based on our inability to access those sites from the browser.
I just loaded hola unblocker on my phone and I find that I can access the sony sites with the Hola VPN enabled.
I don't know if this is Sony's working or 2Degrees, but it seems to coincide with 2Degrees new offer to offer google music to their subscribers, which of course is a competitor to Sony Music Unlimited. Maybe it's just me be paranoid :D