To plot the Bode plot, you need the transfer function.
[A,B,C,D]=LINMOD('SYS') obtains the state-space linear model of the system of ordinary differential equations described in the block diagram 'SYS' when the state variables and inputs are set to the defaults specified in the block diagram.
If your Simulink model is just a transfer function of the controller connected with the transfer function of the motor plant model in a unit feedback, it might be better if you do it in MATLAB.
You can use tf(),ss() or zpk() to specify the controller and the motor model. Then you can use connect() to connect the model with feedback and close the loop. use step() ans stepinfo() to see the step response.
Check the help documentation for all the functions mentioned above. Sometimes its easy to do it in MATLAB without Simulink. But Simulink also has advantages. It's graphical, interactive and can easily add non-linear and time-variant components.
To draw zero-pole plot, use pzmap().
Most of the functions require the Control System Toolbox. If you have that, sisotool(), ltiview() may be very useful.
