The BioShock games probably won't ever be made BC. They were announced late last year, but apparently 2K was already in the middle of porting them to the current consoles, and why would you give people the old games for free when you can sell them new "remastered" versions instead? So the Xbox 360 versions are kind of stuck in BC limbo.
Anyway, be sure to check out BioShock: The Collection for Xbox One, available at a retailer near you, for $49.99.