It depends if he sent two separate texts (one to each of your phone numbers) or sent one text as a group message to both of your numbers. You received an SMS from him on your personal phone. Since iMessages was turned off on your personal phone, all messages between the two of you would have been sent and received as SMS. It doesn't matter that he had iMessages on because you didn't, so it had to go through as SMS to your personal phone. As far as messages being sent to your work phone, yes, they will be sent to it as an iMessage if he sent the message separately to that phone number. It would be sent and received as an SMS if he sent the original message as a group message to your two numbers.