The bulkhead is pvc...there are 2 ways to do it if you want to use flexible tubing. You could buy a pvc fitting that fits into the bulkead and buy some flexible pvc pipe (same size) and glue it all together with pvc glue (use primer too).
Or you could buy the right size hose barb fitting and glue one into the bulkead and plug some flexible hose onto that and clamp it.
Not so sure I would clamp a hose strait to the pipe but I guess it would work. I'd still opt for getting the proper hose barbed fitting since this is what they're made for. But yes, use pvc glue and primer.