An absolute bonus; it does not alway work out that way. ^
EWR-/-PSP on the same one segment flight number would be credited for 2358 miles*, so that's 120 SC's.
EWR-DFW-PSP with 2 flight numbers is 2 segments, one of 1372 miles, the other of 1126 miles. So thats 120 and 90 SC's.
Also you get another 350 QFF points.