Thank you for bringing your question to Just Answer!
You are doing all the right things to keep a long-distance relationship alive. To expect to grow closer while apart may be unrealistic. People grow closer through shared experiences and going through life together.
You could try writing to each other about the big life issues: how will we handle money when we're together? How many children would each of us like to have, and what religion, if any, will they be raised in? Once there are kids, should the wife keep her job?, etc, etc. You could come up with one big question each week, and each one write out their response at the same time, so the answers aren't influenced by each other. These are the kinds of things that usually get hammered out in person, so take this time apart to really get to know where each other stand on the big issues.
Money, children and religion are the big stress areas in marriages--make sure you both are on the same page before you uproot your entire life to be with him.