The major difference is that the TMS FNC Planner is fully cross-platform and cross framework. TMS VCL Planner is for VCL Windows applications only and the TMS FNC Planner is for VCL, FMX, LCL applications for Windows, macOS, iOS, Android, Linux and also for web applications with TMS WEB Core: http://web.tmssoftware.com
For VCL Windows applications only, the VCL Planner has some more features like drag & drop support to a waitlist, balloon hints for example and a few other Windows specific features.