[Trent Adams]

What I would try is getting bbpress site 2 using the WP 1 users directly. Try using the cookie information from the docs:

If bbPress is not installed in a subdirectory of your WordPress install, you’ll probably need to adjust both bbPress’ and WordPress’ cookies to meet your specific requirements. Below is a brief outline of the variables and constants that control the cookie behavior in the two programs.

PHP bbPress WordPress

name $bb->usercookie USER_COOKIE

name $bb->passcookie PASS_COOKIE

path $bb->cookiepath COOKIEPATH

path $bb->sitecookiepath SITECOOKIEPATH

domain $bb->cookiedomain COOKIE_DOMAIN

Trent