WordNet (r) 3.0 (2006):

bipartisan
    adj 1: supported by both sides; "a two-way treaty" [syn:
           bipartisan, bipartizan, two-party, two-way]

Moby Thesaurus II by Grady Ward, 1.0:

22 Moby Thesaurus words for "bipartisan":
   biform, bifurcated, bilateral, bipartite, biparty, dichotomous,
   double, duadic, dual, dualistic, duplex, duplicated, dyadic,
   identical, matched, partisan, party, twain, twin, twinned, two,
   two-sided