what spec would be recommended for pvp as a shaman elemental or enchantment?

If you want do just mess around in BGs, go enhancement. Sadly, elemental was one of the strongest pvp classes in the end of Wrath, but it has become very VERY weak. Enhancement has its downfalls, good burst damage with gear, but outside of ghost wolf, you have limited mobility.

If you want to do arenas, or overall be able to do VERY well, resto is the only true pvp option. I know, you didn't list resto, but resto shamans are very strong overall in arena situations, and sadly both of the dps specs are currently inefficient. Elemental was once great, and honestly Enhancement has never performed overly amazing ever in the 6+ years the game has been around.

TLR, resto if you are serious about PvP, else, enhancement.