You need two PCs. One PC which runs the programs that need the turtlebot hardware like minimal.launch, 3d sensors.launch, teleop etc. This PC is the turtlebot PC to which the USB cables from create/kobuki base and kinect are connected. Workstation PC is theoretically not needed, you can run everything on TurtleBot PC. But if you need to run powerful apps for navigation, planning etc, you will only end up burning your turtlebot pc with atom processor (one that comes with the robot usually). In this case you need another powerful laptop which can listen to turtlebot related topics and do the job. Even if you have a powerful laptop, as in your case - an apple PC, imagine you are teleop-ing the robot. You will have to run behind the robot as it moves. Not a good scenario. So, using two laptops is must, TB PC attached to the robot and Workstation PC connected wirelessly to the TB PC.
Answer to comment:
I don't think turtlebot packages are available in Windows version of ROS. So, yes you need two laptops both running linux. Or atleast, the one connected to the robot has to run linux and may be the workstation can run windows but I am not sure how far that ll work. So both running linux is best solution.
If both the laptops are setup properly, you can easily establish a connection going through this tutorial. Everything is clear there.