Importing relationships
Thanks Paul - it turned out that relationships needed to be set up at contact type level, not as a contact sub type in order for the relationships options to be displayed in the import screens.

So where contact sub types had been set up on earlier versions of civi, the relationship had to be changed to conctact type leve i.e

individual to individual
not Individual (parent) to Indiviudal (child)

The relationship names can stay the same just not the level.