At a property im working that needs main ex bonding doing, the gas meter is in the garage, which is seperated from the house (5m or so). So.. as you would normally take a 10mm from the met to as near the gas meter as possible, on this circumstance would you bond it within 600mm of it entering the house?  any advice much appreciated.

as zambs said.

out of interest what route does the gas pipe take to get to the house?

I agree - bond at point of entry to house - externally if the internal pipework is concealed.

Use a blue clamp (damp environment).