Two sites two domains…goal=one network

i have a satellite office with it’s own nt domain. i am considering installing a dedicated t-1 line between these two sites

Networks use 2 different non-routable address schemes i.e. 10.x.x.x and 192.168.x.x

would it more practical to create trust relationships between the the two domains or to make the smaller network (<20 users, 1 dc) a subnet of the larger network? Any ideas or thoughts are welcome..