Strive to integrate

Strive to integrate your two brands into your sponsorship opportunities. Here's a great example of what I mean.

Lincoln Center has partnered with The Wall Street Journal to present 
Summer Scoops Live with The Wall Street Journal. It works extremely well because:
  1. The name of the series relates to both brands' strengths. 
  2. The visual identity of this series incorporates The Wall Street Journal's trademark use of line drawings, rather than photos, to illustrate the text.
  3. Most importantly, the series enriches the audience members' experiences of either Lincoln Center's programming – several events preview upcoming events at Lincoln Center – or of The Wall Street Journal's writers and editors – through special opportunities to see and hear these individuals speak in a live forum. Presumably, this partnership makes possible these unique experiences for both entities' audiences. 

Sticking a logo on marketing materials does not constitute integration. A stronger strategy is to weave your two brands together.