Green's in marginal starter territory. His +/- numbers the last two years have been pretty bad as a starter, but he did better off the bench behind Pierce.
Likewise, Bass had pretty bad +/- numbers the last two years, but this year off the bench he's looking quite good.
Rondo and Bass both had better numbers as starters as late as '11-'12, when they were still playing for a good team.
So yeah, with +/-, teammates and bench vs. starter opponents can significantly affect even players' longer-term numbers.