Doesn't Clan Wolf in Exile have Kerensky Bloodlines as well? So wouldn't that make 100 in total?
I may be wrong, but I think they way it worked, when the Xies were abjured, the Grand Council abjured the blood legacies of the Bloodnamed that were part of the Exiles (with the exception of Phelan's Wrd legacy, which was stripped and given to Vlad). Thus, there are two sets of legacies, thise held by the Wolves and those by the Exiles (theones that were abjured). The Wolves obviously don't use abjured legacies, but the Esiles, being abjured, I woukd guess don't get access to any bloodrights to names still held by "real" Clans regardless of heritage.
So each has their own set of bloodnames, with the total bloodcount between them being less than 25 (to account for reavings and such over the centuries).
Though, just a thought. Each could in theory allow rejuvenations independant of each other, and thus raise the bloodcount for each bloodname over 25.