Problems setting up multisite Buddypress

Hi
I’m setting up unews.buzz as a multisite Buddypress, using BP Multi Network so each subsite has their own community.
I’m missing something, so am struggling to set it up on the first subsite politics.scot.
I’ve implemented it on another site, and there it offers me Buddypress options (registration pages etc) at the subsite level when I go to Settings on that site.
It doesn’t show on politics.scot the same way, so I’m unable to set up the site to begin using it.
Any ideas? I have enabled Support Access.
Thanks, Neil.