Ah, yes, you're right. It appears those domains are owned by Apple. I wouldn't have thought that, but some investigation confirms it.
iPhones will attempt to load a page in the background when connecting to a wifi network, to trigger any login page that the network might require. If that article you point to is correct, in iOS 7, those domains are some of the ones used for this purpose. I don't know why that would be... seems weird to use suspicious-sounding domains for this purpose!
I'd guess that your office network is blocking access to some of these sites for some reason. This would explain why it works 50% of the time. You may want to talk to your office IT guys about this.
BTW, note that Apple does not respond to questions here... this is a user-to-user forum. If you want to talk to an Apple rep, your best bet is to make an appointment at the Genius Bar at your local Apple Store. (You could call support, but they'll probably want to charge you for the call.)