Haven't had a fish on straddie in a loooong time (mainly offshore these days), but from what I remember the top spots were as follows:
-amity spit just a little south of jetty(bream, whiting, flathead)
-amity rock front, anywhere. (luderick, bream)
-dunwich, near jetty off rocks in front of mining facility (bream, squire)
-dunwich jetty (bream, squid, have caught golden trevally off jetty before)
-dead man's grotto, find a gutter if there's one (bream, tailor, dart)
-main beach, find a gutter (bream, tailor, dart, whiting, my grandfather caught a 50cm summer whiting off this beach once)
Ask the locals though, they're always pretty helpful. I'm sure these spots would still yield some decent results, maybe not as good as back in the day though.
Good luck anyways mate.