If there were an official clarification, I believe crossblooded and bloodline familiar both work as archetypes that modify the same ability. So they wouldn't stack.
But without that clarification, it relies on each DM to determine how that works in his own campaign.
Bloodline familiar is not an archetype, but a (vaguely defined) "option", similar to Variant Channeling and Sin Magic. IMO, it would have the ability matching the ability it replaces.