I have a book of pro-pro 9x9 games, played with 5.5 point komi, so the pros thinkJapanese pros have been playing 9x9 with 6.5 komi (the games shown on satellite/cable) for a number of years before the 19x19 komi switch.
5.5 is correct (although they just switched to 6.5 on 19x19).