Native promises and bluebird use different microtask queues on Node which makes interop incorrect (which is also one of the reasons why bluebird is ES6 spec non compliant). See https://gist.github.com/anonymous/9936c695f2c29e79a0c1a0dec8...
This might lead to subtle ordering bugs, I would recommend against using both together.
Using bluebird and native promises together may result in slower performance because V8 has fast paths for native promises which fail for bluebird.