Probably wouldn't result in much beyond a more concrete appreciation of each other (as both viewed each other under shrouds of intense mystery), but the Han from Gan Yin's accounts already had viewed the Roman Empire as a near-equal, naming them the "Qin" (so-named for their "like-ness"/civilness to China with respect to other barbaric entities).
Direct trade would still be difficult, and the Han were overly concern with the Parthians and later conflicts with the Kushan Empire. If the Han doesn't consolidate Central Asian and Bactria, there's little need for them to be involved in Parthian affairs (and thus would not even think to have political relationships with Rome).
I mean the Eastern Han did receive a Roman mission in 166, but nothing concrete came out of it. Of course the Han influence in Central Asia had certainly waned a lot more by then, it shows that the court wasn't overly concerned with something that's even further than the gratuitous Central Asian lands