You might want to contact your corporate travel department and see if any one there knows the terms of your corporate rate. Although most companies get a boilerplate contract, some actually negotiate additional benefits and this may include the elimination of benefits in return for a better rate.

That being said, there have been reports where properties have determined since you are getting reimbursed by your company or using a CC branded as being Corporate, that you are not paying for your room and therefore not entitled credit for the stay. Fortunately, that has been shot down just about every time.

Good luck with your research.