Yes indeed. I think that the versions you have are not designed to have 2 phones. You steal the registration on the server like this.
However good news - when we release the new ios client, (14 feb onwards we will start sending out updates) it will work. Actually I confirm that I have this setup working with an iphone and android configured on the same extension. I can confirm that they will both be pushed. However I still believe that sometimes one phone might steal the registration of the other. So not a guarantee this will always work like this.
So now you can become like me - a confused madman running around with a different android every day and iphone. not fun. I do this because I have 2 apps that I need to manage and ensure that they both work properly. this is why. Otherwise trust me, I would stick to one os.