The genuine Apple adaptor contains a D/A convertor (the 30 pin interface included analog audio, Lightning doesn't).
I'm guessing the Zeppelin takes an analog feed and doesn't have a built-in D/A. B&W say the Apple one should work.
It's possible that if you got a non-Apple adaptor which doesn't have one.
I’d expect it to. Your adapter was just a power pass through - couldn’t pass audio over lighting bit. The only purpose of a BT adapter is to receive (digital) audio, it would be strange not to output it in turn..
The genuine Apple adaptor contains a D/A convertor (the 30 pin interface included analog audio, Lightning doesn't).
I'm guessing the Zeppelin takes an analog feed and doesn't have a built-in D/A. B&W say the Apple one should work.
It's possible that if you got a non-Apple adaptor which doesn't have one.