Lemon Laws vary from state to state.  I doubt if it matters which
dealer you use as the law usually applies to the manufacturer.
However, unless you have reason to think that this dealer has an
incompetent service department, I would go back to them.

Your goal should be to get it fixed rather that use the lemon law.
That said, three unsuccessful attempts at the same repair is a common
standard for triggering the lemon law.  you need to check your state's
laws.

It's possible that there was oil left somewhere on the engine or, if the
initial leak was large enough, back behind the engine under the car.  I've
seen leaks from head gaskets that were allowed to go on so long that there
was oil half way down the car underneath.  Anyways, if the dealer where the
repair was done didn't steam clean the engine, then it could be a source for
the new oil spots.  If that's the case, then take it back and get it
cleaned.  Afterwards, keep a watch out for oil drops as well as regularly
checking the oil level.  For what it's worth, stick with the dealer that did
the repair and make sure they get it done right (if it was me, I wouldn't
try to fall back on the lemon law just yet).

Eric

    I have seen the seal leak because the crank was causing the problem.
Leak stopped when the crank was replaced. Customer was back four times
before it was fixed for good.     bob

I would go back to the dealer which did the repair.

So far you are nowhere near lemon law status under any of the state laws
 I am familiar with.  One problem which may or may not have been
properly repaired does not make a car a lemon.