Normally the programs are independent. Earning miles goes to one program and that program sets its own expiry date policy. To postpone expiry (which is possible with every reward program I know but it might not be the case for all) you must have activity in the account whose miles are about to expire.
Any activity will do, so you can fly with another Star Alliance member and have them credit the miles to the account you want to postpone expiry. Also, flights are not necessarily needed, you can spend with a partner which are numerous (flower shops, hotels, cars, etc, depending on the program). The point though is that the activity has to be in that account, not any other one, even if it is with Star Alliance.
Victoria has a set expiry after 3 years of arcual which can be extended for a charge. Many other Star Alliance programs though, such as Aeroplan by AirCanada and Mileage Plus by United Airlines, do not have a set expiry but the whole lot of miles gets its expiry pushed forward when there is activity in the account. These are distinct programs from Victoria and so getting any of these will not prevent current Victoria miles from expiring.