Bloodlines are strange and broken things, that's why they aren't used often.

I won't go into much detail on bloodline cheese but here's the gist of it.
Bloodline levels stack with any classes for anything based directly off class level , so a level 5 binder with 3 levels of Bloodline would bind as a level 8 binder. Add in a single level of a binding prestige class and that adds up to a level 12 binder, that would be a level 6 binder binding as a level 12 binder, then would gain another 2 effective binder levels for more levels of binder or the prestige class, and would then gain another 4 effective binder levels for any different binding prestige classes.