This is something you can't do just through normal constraints.
You can't make spaces equal to each other.
What you need to do is use invisible "spacer" views and make their heights equal.
So you would have something like...
// in pseudo VFL
V:|[topSpacer][titleLabel]-[subTitleLabel][bottomSpacer(==topSpacer)]|
Make the topSpacer and bottomSpacer alpha = 0
or hidden = YES
and it will hide them but they will act as layout scaffolding.
By doing this the gap above the titleLabel will be the same as the gap below the subTitleLabel.