I own a vacation cottage and I use Realty Company A's service to
schedule and rent out my cottage for 12 weeks of availability with a
year to year contract.  Realty Company A does not allow me to know the
renter names and addresses for my cottage and many of them repeat rent
my cottage same week each year.

Recently, another realty company, Realty Company B, bought the entire
rental operation from Realty Company A, which means all of the cottage
owners like me have to stick with the new Realty COmpany B if I want
my repeat renters to now rent my cottage through new realty company B.
 And
I still cannot have access to the repeat renter names/addresses for my
cottage.

It was not my decision nor was I asked for approval/vote on the
buyout, and I do not like working with the new Realty Company B. 

Do I have legal grounds to request that I want no part of going to the
new Realty Company B, and as part of that can I ask for the list of my
repeat
renters names and addresses so I cna contact my own renters from here
forward?

I don't know the answer to that, but presumably you have access to
your own cottage for repairs, improvements and inspections etc. I
would leave a Visitor's Book in the cottage for renters to fill in,
somewhere not too obvious, like in a bedroom drawer, or perhaps
comments slips with your address on them. Over time, that should
collect you the names of those people who don't mind being contacted
by you.

If the cottage has a phone, you might call every week, speak to the
renters and explain your situation.