A condition of your Tenancy Agreement requires the Landlord to give each Tenant a copy of the entry key and any other opening device / information (e.g. an access code) “for the premises and any common property that they’re entitled to access”.
Note that the wording is ” give” not charge for, other than for a security deposit that must be refunded when you hand back the keys/devices, that it’s “entitled to access” not just “reasonable access”, and that the provision applies to each Tenant named on the Agreement (Lease).
So if you genuinely need another remote, then you should ask your Property Manager to include your housemate on the Agreement (unless that’s been done already), and then ask him/her to approach your Landlord about arranging that additional remote with his Strata Manager / Owners Corporation as the Agreement and the NSW Residential Tenancies Act (RTA) requires.
BTW the provisions of Sect 70 (2) the RTA apply as they’re superior (at law) to any Special By-Law that the Owners Corporation of your Building may have concerning security access or similar matters.
Now that you’re almost “IN”, I just hope that you do as you stated in your first post, by legitimately accessing the visitor carspaces only for your short term visitors, and by using the gate to get your bicycle in and out of the garage; if you don’t, then RTA or not, the Owners Corporation can (and should) come down on you like the proverbial ton of bricks.