I have a question. What is the best Star Alliance program for my wife?

I was thinking either BMI or Air Canada. I credit my kids leisure travel to Air Canada, and have been happy with that. However, if I combined the Hilton Double Dip (50 nights) with my wife's work travel in BMI that would add up.

When she travels for business, she travels in premium cabins: C in 3 class and F in 2 class. When she travels for leisure, she is with me and so doesn't need E+ or other benefits from United. In total she travels around 60,000 miles per year and is based out of Los Angeles. The split business/leisure is about 50/50.

Thoughts? Pros and Cons?