Hi Brandon,
There is only so much you can do in post if the subjects are really dark. I’ve been shooting weddings for 20 years, and I always shoot to properly expose the couple and just don’t worry about the background. Learned this the hard way, courtesy of second cameraman.
Many times I’ve had to really blow out the background to where it is just white, but the important thing is that the couple is more than a mere silhouette. Of course you can sometimes pick a happy medium where the couple is bright enough that you can give them a bump in post without having a totally blown-out background. Comes with experience I guess, no easy answer as every situation is unique.
As I use Matrox color correction plug-ins, can’t say which is the best native Adobe tool for the job, but probably a 3-way color corrector that will allow separate adjustment of shadows, midtones and highlights, or curves may even be better.
Good luck with your fixes
Jeff Pulera