With each channel of your business, you are faced with the question of creating a new logo or not.  The best practice for brand channel logo creation is to use the original logo in the design of the brand channel logo.  This can be as simple as adding text under the main brand or the right of it. 

The reason to do this is to leverage the brand recognition of the core logo.  This can be seen in Richard Branson's Virgin companies.  Every channel and brand within the company uses the Virgin brand.  Virgin Airlines, Virgin Mobile, etc.  If he were to create a new logo for each division, then he would have to start from zero in regards to brand equity.  The Virgin brand is already worth billions of dollars.  Each channel brand uses the existing brand equity and reinforces the Virgin brand, adding more equity to the brand.