The current version (8.0) does support Visual Studio 2012. However seems like we haven't updated the "supported VS versions" field in time: will fix that right now, thanks for bringing this up to our notice.
Sanny, even though you don't use ReSharper, in order to integrate the TeamCity plug-in into VS2015 you can download the ReSharper Ultimate installer from http://www.jetbrains.com/resharper/download and choose to only install the TeamCity plug-in.
Boost Test and CppUnit test runners are both supported via plug-ins.
Then of course, you have language-independent support for major version control systems and IDEs (there's a TeamCity plug-in for Visual Studio).
Tomas, thanks for the question. The latest TeamCity (version 8.1) in fact does support VS2013. Please download the build from TeamCity web site (http://www.jetbrains.com/teamcity/whatsnew/) We'll update the build here on Visual Studio Gallery in a short while.