I am using Yosemite on a Mac and my daughter is using both windows 7 and windows 8 on a PC. Language is english. I want to know the answer for all components of Libre Office.
I think it will work fine. It might be a good idea to stick to the open document formats though (.odt for documents, or .odp for slideshows for example). The open document format should be the one that is chosen by default when you save something.
I would want to make sure you are using fonts that are available on both OSes.