2-step verification issues with my iPhone

Hi, I have been having problem accessing iCloud via two-step verification. The code I request never arrives on my (registered) phone number so I have to resort to the Recovery Key - an unwieldy code to keep close. I have recently registered my partner's phone to my account - and Apple will happily send him a request code for my account all day long! So annoying. Any suggestions gratefully received.(Yes, the phone number is correct) I'm a long time Apple user but Yosemite has me at my wits end. I assume this is another charming side effect? Cheers.