difference between 人缘儿 and 谈得来
I would say '有人緣' is used to describe a person, like '他很有人緣' means 'he always gets along well with others'.
'談得來 'is used to describe a relationship, usually used when 'two people' are getting along well, like '我和他很談得來'.
But you could still use '他和大家都很談得來' 'he gets along well with everybody'.