If you go on the Jefa site, click Spares and then Bavaria you will find a list of models, including your 33. In that file is a number of PDFs of both the rudder assembly and components. As you will see the tube, which is bonded into the hull, is aluminium, as are the stock, key and the locking nut. The bearings are non metallic, self aligning roller bearings. There is nothing there that would cause galvanic action, therefore bonding to an anode is unnecessary. The screw clips holding the gaiter onto the tube and stock will be stainless, but they are insulated from the aluminium - and not in seawater anyway.
BTW have just been down to my boat to check that my memory was not playing tricks on me and just in case I had missed something. My boat is Coppercoated right up to the spacer so no need for the Trilux that I used on the old boat. However, not sure it is needed anyway as this steering system does not have the exposed aluminium bearing housing of the earlier boats, so just avoid getting copper based antifoul on any exposed rudder stock.