I couldn't find an existing category for that cemetery, but one could be created. It should be called Category:Concordia Cemetery, Buffalo, New York, and should be a subcategory of Buffalo, New York, and Erie County, New York, Cemeteries.
There should be both a freespace page and a category page for any cemetery that is having a transcription posted on WikiTree. The transcription should be on the freespace page, with links to the profiles. That page and the profiles of people buried there should be in the category.
If you created that spreadsheet, or have permission from whoever did create it, then yes, you can use it for the Global Cemeteries Project! Just let me know if you want the project badge, and you might want to check out the challenge we're having in January!