No. But brand dilution (the use of a logo in conjuntion with ever-expanding markets or activities) and brand standards (appropriate characteristics and presentation or a brand) are separate issues.
Many orgaizations have limited, but defined logo variations, based on the surrounding document/presentation/package. Look at what other people do as a guide. For example here are the
American Red Cross Branding Standards. Google "Brand Standard" for some more ideas.
In your case, these look to be the two primary variants based upon the nature of the surrounding field in the medias and look fine to me.