Different bonuses stack, like bonuses don't, generally speaking, so, yeah, they should stack. Both being force effects should be irrelevant, a steel shield and full plate are both metal, after all.
both are Force Effects, but one gives a shield bonus, the other an armor bonus...
thanks,
GRU
Yes they do.... basic tools for the wizard starting out on the AC race. For stacking purposes it's the bonuses that are the main question, not the effects.