If I understand it correctly
a) you want to use TeraTerm terminal emulator on a netbook PC as a remote serial console allowing you to log into your Linux machine.
b) instead of using a plain serial wire you plan to use a pair of USB bluetooth devices to transfer the characters between the netbook PC and the Linux machine.
c) you have already got the netbook PC end working
At the linux end first check that the USB bluetooth device is detected and shown by the "lsusb" command when plugged into a USB port.
Provided it is detected you next need to ensure that the correct linux driver is loaded to provide the /dev/ttyxxx serial device. I don't know much about this process. On Debian Linux drivers are loaded using the "modprobe" command and this command is normally ran automatically to load the correct driver when a device is detected. It can be ran manually to load the driver if device detection isn't configured to know the driver to load.
ExGrunt in his message of 25th Mar 2015, 17:51 seems to know more about this than I do.
Once you have the /dev/ttyxxx serial device you could test it with a terminal program such as minicom, cutecom or Putty (this will just allow characters typed at one end to be displayed at the other). To actually allow you to login and run commands from the netbook PC you use the command "getty" (or similar). See
Configure getty
It should be possible to configure the Linux machine's device detection to both load the correct driver and start "getty" when it detects the USB bluetooth device and also send the hangup signal to the getty process (plus any child processes) and remove the driver when the USB bluetooth device is removed.