WiiFlow 1.1 since R23 was compiled using devkitPPC r18 or r19.
Since R39 it was compiled using devkitPPC r21 and libogc 1.8.3.
Since around R374 Wiiflow was compiled using devkitPPC r23 and libogc 1.8.7
Since around R400 Wiiflow was compiled using devkitPPC r24 and libogc 1.8.8
All required portlibs are included in the source and dont need to be bothered with for compilation.

