The main fishing area at bobbin head is really a baby bream nursery... having said that, the odd thumper bream and tailor come from here as well as many good mullet. Another place nearby you could try is apple tree bay. It is the next bay around from bobbin head and a much better fishery! Bream, Flathead, Whiting, Tailor, Jewfish, mullet and blackfish come from here. Balmoral is another option. Prawns will get you flathead, bream and flounder. Balmoral is in middle harbour.
With the kayak, you can fish a few different waterways. I would recommend upper middle harbour and cowan creek. Upper middle harbour is very sharky (bull sharks) but it has plenty of bream, flathead, whiting and jewies for both lure tossers and bait fisho's. Cowan on the other hand, is a little more productive. It is a relatively deep waterway and holds really good numbers of bream, flathead, jewfish, tailor and hairtail (hairtail only in winter) aswell as a few whiting, blackfish. It has endless deep water banks that are a bream fisho's paradise. Blades and SP's are best but unweighted prawns will do the job aswell. If you are after a challenge then i recommend you get some BIGGER SP's out and have a flick for jewies. They are very elusive but its well worth the effort! Paddle tail type plastics are best (5"+)
Cheers, Tom