Well I'll answer my own question. After doing some more reading it appears Bing and Rainier will pollinate each other. I guess that's why I got a few Rainiers last year.

I was under the impression that Bing and Rainier Cherries wouldn't pollinate each other. Isn't Bing one of the ancestors of Rainier?

jwm:

Yes, Rainier is a Bing/Van cross, but that genetic change resulted in a cultivar that will pollinate Bing. Starkrimson is called Lapins by everyone but Stark Bros., and will undoubtedly supply some pollen too.

I hope you are able to raise these large crisp cherries in Alabama without cracking. They are sure hard to raise here in N. Virginia, with its combination of heat and humidity during the ripening period. Lapins is softer and should be easier. Sweet cherries seem to be a delicate task just about anywhere they are raised.

Don Yellman, Great Falls, VA