On the subject of the preservation of brick piers in any of the Eastern
states - In the first place, you have to determine the condition of the
bricks.  Are they soft, low-fired bricks?  If so, they're going to
deteriorate, and they'll do it faster when the fungus and mold from being
sealed in plastic get a grip on them.  If they're solid, hard, highly fired
bricks, then you can probably pour coca-cola on them and they'll be fine.
 
I've had reasonable success for a short period of time (a couple of seasons)
in a wet climate by perforating the plastic sheeting, covering the feature
with the well perforated plastic, then with sand-bags, and then backfilling.
 This won't last forever.  Nothing will.
Whatever you do, don't seal in the moisture.
Listen to the conservators, consider your resource and your goals, and then
make a compromise.  It won't be perfect, but it may satisfy some of your
preservation and presentation needs.
And, by the way, San Diego is a LOT drier than where you are.