I think I'm confused but isn't this more like what he actually did by mentioning that it bothered him that I never called rather than what I should do in response?
Your initial impulse was to 'do' something for him out of empathy/sympathy... old pattern, you recognize. The ISSUE, however, is that you have not, in fact, met yet, and you have, in fact, been clear with him on this 'exclusiveness' thing. To me, the man should be hopping on a plane to come and see YOU, if he is, in fact, worried about this: "I know you are less optimistic about this relationship than me because you never call me."
My first response would be... "HUH? How are you coming to that conclusion?"
Point in fact, he is Captain of Industry, and if he has so much disposable income as to fly YOU around, he has the money to fly himself around. Honestly, I think it more appropriate for him to fly and see you the first time...
So what he was, in essence, inviting you to do... is 'pursue' him. Nice ego jolt for the emotionally distant/unavailable. I can promise you... you start doing that... he will start calling less, and let it all fall in your lap... calling, emailing... etc. He needs someone to take care of the R, kind of thing. EU people will do that... and your cow is going to come climbing out... ewh. He hasn't EARNED your cow, Mo... you owe this guy NOTHING.
On your end... you are just fine and dandy with how you feel about him at this point. I suppose the next time he calls, or drops some hint to that effect again, you can say... 'whether I call or not has nothing to do with my optimism about our phone relationship. Actually, I think it is rather well placed, considering we have not yet met. I think it is good to 'want things, to wish for things. Keeps things interesting, don't you think?' Or some Mojo way of saying that.
You throw it back in his lap in a teasing fashion, but you don't go in and 'rescue' him by now starting to call. Men like to pursue, especially someone they aren't all that sure of... on your end... you have to SIT on your cow... and understand that the most empathetic thing you can do for this guy is make him work for something, if he really has an interest. If things come too easily for them... they get bored... because you start running the R FOR them. Can you say... Secretary to your C of I?
Like NOP says... why buy the cow when you can get the milk for free? Right now, the guy is 'buying the cow.' Don't worry. It's good for him.