Maybe, their has been some hints when Stoica saw the picture of Julie, Dan, and Runo in episode 22 so she may be captured by the Gundalians to pursue Dan into giving up the war between Nethia and Gundalia but we don't know yet.
Runo is a very important figure to Dan, so it is quite likely that she will appear. The seventh episode of Bakugan Gundalian Invaders was supposed to be called The Revenge of Runo but this was...