When the Roams are connected to the same WiFi network, yes.  You can set up a stereo pairs or group separate rooms together.  if only connected to bluetooth, then no.  The one exception is that some android devices can make separate bluetooth connections to 2 roams at the same time.  The Roams are not coordinating with each other or play stereo in that scenario.  It doesn’t even need to be two Roams, any 2 bluetooth speakers would do that.

Mod edit: Corrected “and” typo to “any”