In redirects Google only gives ranking to the final site. If you have some kind of content on each they could each get position then you could link them to the site you feel is your primary site.
Just be sure you have unique content on both. I've tried both. I had a site that had been up for about 10 years. I did a redesign and uploaded that with a new domain. As soon as I changed site one, partyconfetti.com to a redirect it dropped out of the search ranking on all sites. It sucks but you'll have to put content for each