Remote Buddy does support global keystrokes and does issue them by 
default. You'd have to explicitely select "send keystroke directly to 
application" to have it not send a global keystoke.

Remote Buddy uses the standard OS X APIs to emulate the keystrokes, 
which generally works very well. OS X adds these keyboard events on a 
level that's located higher than the HID device level, though.

Therefore, applications that directly listen to input on the HID 
device level inside the kernel and make the active decision to ignore 
the standard OS X high-level keyboard events, will not see these events.

I didn't look at ControllerMate, but if it works as I think it works 
from its website, it does only support input from HID devices which - 
usually - means from real hardware only. It looks very hardware- 
centric. If ControllerMate supports normal OS X keyboard events, it'll 
also receive those sent by Remote Buddy. If it doesn't, it lies in the 
nature of how normal OS X keyboard emulation works, that it can't 
receive them. Likewise, then, ControllerMate would also not be able to 
receive keyboard events coming from a screen sharing session.

Best regards, 
Felix Schwarz