I've done this on many versions for years. Generally speaking, any issues, especially when moving from Windows to Mac, are pretty minor.
Both machines may or may not have the same fonts installed. If you database layouts specify an unsual font a different font may be substituted when you open the file on the other OS and this may change the appearance of your layout. If you use "plain vanilla" fonts, this should not be a problem.
Windows machines require a slightly larger amount of space to display the same text as Mac. Thus minor changes sometimes appear when moving a Mac file to windows. Since you're moving files the other way, this shouldn't be an issue.
Thanks for the Info. :)