Should I ground my TV antenna?
Yes, you should have a grounding block wired to a ground rod before the antenna wire enters your home. It won't necessarily prevent all damage from a direct lightning strike, but it will help.

NEC in the States (NFPA 70) says that if you don't ground the grounding box to the same ground rod that is connected to your breaker box, you need a #6 wire between the ground rods. Obviously, that doesn't apply in your locale, but it's still a good idea.

YMMV, but I get excellent digital TV reception from an antenna mounted in my attic. Removes all the worries about grounding, wind, etc.