Hi is it safe to socialise a new unvaccinated puppy with her vaccinated house mate that is upto date with his boosters

Yes, you could hardly keep them seperate and if you did that wouldn't bode well for future relationships!

ive always let new pups in my house play with our other dogs they need to bond x

Yes, once my toy breed puppies are up on their feet, they get introduced to the Collies.  Stops them being silly and frightened of big dogs. 

Puppies bought in get to socialise pretty fast.  I find the earlier that they are introduced, the quicker they feel at ease.

Most puppies come from breeders who have more than just the mum so have been around other dogs to some extent anyway.  As long as other dogs have been vaccinated there should be no problem.

Same here.  My 5 week old pups are out with the other dogs too. :)