It sounds like you are paying for a renovation, but the question is, should you be. The owners corp has to fix the leaking floor, this much we know. Now, if fixing the floor means damaging the wall tiles, then they have to fix them too. And if fixing the wall tiles means replacing the fittings … you get my drift.
The fact that the new tiles and fittings are being excluded from the costs to the owners corp makes this feel just about right to me. As for the labour costs? Hard to say most of them wouldn’t have fallen to the OC anyway.
Should you wait until the waterproofing fails so you get a big contribution towards your bathroom reno? That’s up to individuals and how long they are prepare to live in a flat with a 40-year-old bathroom