Open MPI does require the F77 bindings for F90 support.  Hence, if you want to use g95, you also need to have the F77 bindings configured and built.
From the output you sent, you ran "./configure FC=g95".  Configure did not find a valid F77 compiler, and therefore skipped both the F77 and F90 bindings.
Can you try:
    ./configure FC=g95 F77=g95
    ./configure FC=gfortran F77=gfortran
You said you tried the formed but it died in configure -- can you send the configure output and config.log from that run?

From: [] On Behalf Of Terry Reeves
Sent: Wednesday, May 24, 2006 11:25 AM
Subject: [OMPI users] Fortran support not installing

Hello, everyone.

I have g95 fortran installed. I'm told it works. I'm doing this for some grad students, I am not myself a programmer or a unix expert but I know a bit more than the basics.
This is a Mac OS X dual G5 processor xserve running OS X Server 10.4.6. I have xcode 2.2 installed which gives me gcc 3.3 and 4.01 installed.

I do this

./configure FC=g95
make all
make install

then mpif90 yields this
Unfortunately, this installation of Open MPI was not compiled with
Fortran 90 support.  As such, the mpif90 compiler is non-functional.
btw if I try this
./configure F77=g95 FC=g95 it bombs in the configure stage but as far as I know f77 support is not needed but perhaps its useful info.

I have included config.log, config.out, make-install.out, make.out, and ompi_config.h per instructions on the web site.

I have also tried this with gfortran with the same results.

Any help you can give would be appreciated