In WA the definition of a 'sign' includes 'Road Marking' so a road marking can be a bicycle lane sign. Unfortunately in QLD the definition is different and it would not apply.
You have brought this up before and I believe you are incorrect. The regulations are quite correctly pedantic in their use of language (critical in law after all). It refers to and defines bicycle lane signs, road signs and road markings separately. Bicycle lane signs are clearly defined; they are not road signs as per the Regulations and neither are they road markings. You are assuming that bicycle signs = road signs = road markings when there is nothing I can see in the regulations to justify this conclusion.
See regulation 3 which specifically defines a bicycle lane and a bicycle lane sign ... no reference to road signs which are defined separately in the same regulation as are road markings. A quick search of the regulations shows that the term road sign and road marking are used in various parts of the regulations quite separately from the one on bicycle lanes (no mention of road signs or road markings in the bicycle lane regulations). If there where the same there would be no need for the separate term and definition. In fact bicycle lane sign is only used in relation to bicycle lanes.
Note also the repeated use of term "road marking" in the definitions yet not used in relation to bicycle lane signs.
Furthermore Schedule 2 shows a bicycle lane sign and the related regulations that it is applicable to. This provides further evidence of it is specific nature.
EDIT: More critically there is a whole Part related to road signs/road markings. It is Part 8 Traffic Signs and Road Markings. Guess what does not get a mention in this part? Bicycle lanes and bicycle lane signs. These are documented in Part 11 Keeping left, overtaking and other driving provisions, in Part 12 Restrictions on stopping and parking and Part 15 Additional provisions for bicycle riders.