The theme song to TITS2 is called "Soar into the Clouds" (衝上雲霄), composed and sung by George Lam.
Comment: After hearing this, I agree with everyone that the original song was better. This sounds like it's for a '80s kung fu series.
The sub-theme song is "Lovers in the Air" (空中戀人), by Mag Lam.
The second sub-theme song is sung by Raymond Lam, called "On My Way".