Hi Sakura,
Spatial data can be used in both of Euclidean (flat) coordinate system and round-earth coordinate system, and it can work with Bing Map. For more detail information, please refer to the following link:
Spatial Data (SQL Server)
http://msdn.microsoft.com/en-us/library/bb933790.aspx
http://www.bing.com/community/site_blogs/b/maps/archive/2012/09/24/viewing-census-data-on-bing-maps.aspx
Allen Li
TechNet Community Support
