As far I remember (I used these tools extensively at the time), Borland C++ was the bigger, more complete and more powerful package. It was basically the professional version while Turbo C++ was the hobbyist one.
Microsoft took more of the approach I think we're remembering. For example, BASIC PDS 7.x being the more professional version of QuickBasic 4.5.
Boy, remembering that really digs up some nostalgia...
edit: I see the "Borland C++" wikipedia page present it as the successor, but the "Turbo C++" wikipedia page describes it as the hobbyist counterpart. The release dates and version numbers line up really well, so that makes sense. I was a hobbyist at the time.