I can’t see why a monetary penalty would be appropriate. What you want is for the floor to be fixed. You want an order giving the owner a limited time (6 months, perhaps) to bring the flooring (other than laundry kitchen bathroom toilet) to a suitable standard. You could ask for AAAC 6-star which requires thick carpet on good underlay or settle for 5-star which is possible with vinyl if it has a decent acoustic layer underneath. Don’t be fobbed off by compliance with BCA – that’s not good enough. The order should require the owner to supply a certificate of compliance from a reputable acoustic consultant at his expense (think $1500).
That presumes you have suitable by-laws, perhaps:
An owner of a lot must ensure that all floor space within the lot is covered or otherwise treated to an extent sufficient to prevent the transmission from the floor space of noise likely to disturb the peaceful enjoyment of the owner or occupier of another lot.
Also, you’d better ensure you have a written complaint from downstairs.