I don't see why it wouldn't work. Looks like a bluetooth controller, possibly one that also acts as a USB joystick when plugged in that way. I've not tried an extra joystick on my Pandora yet, so I don't know if all emus etc. can be configured to use it, but I've used a USB joystick on linux in the past with mednafen, so it'll work in some ways for sure.
It won't be a patch on the Pandora controls of course. Anyone using it as a second player will be at a disadvantage - you'd be better off with a cheap USB adaptor and your favourite old-school controller. But it might be useful if you're using the TV out cable and want to leave your pandora by the TV while you play on the sofa, without trailing a controller cable across the living room.