Like you said, romance is not the focus of the show. However, they've given us several hints at El Topo and Le Chevre already ("Not YOUR dear boy" and the fact that they are always together) so I think there's a real shot at them being canon.  Other than that, there hasn't been too many other hints at romance. There's the fact that Graham shows interest in Carmen and asks her on the coffee date. However, the writers may not have her with anyone or leave it ambiguous so as not to upset either Julia or Gray fans. Also, Carmen may not want to put people in danger needlessly, so she may decide not to pursue romance.