There aren't many that do. The HTC One and Samsung Galaxy S3-4 are two phones I am aware of that support aptX, sadly the Nexus do not. There may be more now, I stopped researching with my One and my wife's Galaxy
I am in the market for a wireless speaker too, and have narrowed my choices to the KMC 3 and the Peachtree Deepblue. They both sell for the same price on Amazon. On papers the Deepblue look better with a bigger amp and drivers. It also weighs twice as much as the KMC 3. I would love to hear people's opinions about these speakers.