I was just wondering if its possible to move a WA neighbourhood i edited with new houses etc to another home neighbourhood .

IE take the one i have in Riverview and add it to the Bridgeport save .

Do i just copy the two France or China files across from my save folder or is there more involved please

You could copy those files, but its not absolutely guaranteed safe. But on the other hand, I've never heard of anyone borking their game by doing this.
Also take into account how much foreign quests you will have completed.

Not done any quests just rebuilt a lot of houses in those countries and trying to save myself the hassle of rebuilding in each vacation neighbourhood time after time

Ok, that's a good thing.

This is a note I made for myself: lots that shouldn't be edited because they involve missions. Again, they could be safe, but I borked an older game by tampering with one.

EGYPT
20 WEST RIVERVIEW PLACE - MABDOULI INDOOR MARKET
10 EAST RIVERVIEW PLACE - AMIN HOUSEHOLD IS MORCUCORP HQ!
40 WEST RIVERVIEW PLACE - AMEEN (NOT AMIN)(tiny tomb)
1 QUARRYVIEW PLACE - LUFTI (tomb)
7 MARKETVIEW PLACE - RASHID (TOMB)
COPPER QUARRY (PROB)

CHINA
PHEONIX MARTIAL ARTS ACADEMY (because of "convince him to come back" mission)
SHANG SIMLA MARKET

FRANCE
20 PRIMROSE RAD - DUTIEL (tomb)
CEMETERY TOO (has chests)

What i am trying to find out is if i can just move the whole sub neighbourhood to another main saved neighbourhood instead of having to start new sub hoods and rebuild and edit houses each time

You may wish to ask in the Create-A-World forum, since lots of the experienced world modders may not necessarily stop in the World Adventures forum.

No, you can't simply do that. You can move LOTS, sure, but you can't just copy the subhood files over.

There is a way, however, to make a WA world into a base hood using CAW, discussed here (yeah, you gotta read the whole thread): http://www.modthesims.info/showthread.php?t=416989

It is not particularly simple