Can I Simulate a SMPS Compensator on Matlab/Simulink
It's very much possible and encouraged to do this. Since you have the values of your capacitors and resistors, you can write the transfer function of it and replace the variables of capacitors and resistors. Then you can use the bode plot function from Matlab with said transfer function.
However, if you're wanting to also include values of parasitics and whatnot the transfer function becomes more complex and you'll need a circuit simulator instead. But for a first pass and ballpark estimate of where the poles and zeros of you compensator are you can ignore parasitics.