When opening a Vietnamese bank account make sure the bank has a good English language internet banking site, for paying local bills etc. I use Shinhan Bank (Korean) who bought their lisence off ANZ when they exited Vietnam. I like many am stuck in Australia because of restrictions but I can still pay my local bills as their security system is a dongle which generates a security number each time I do a transaction. I use to have both an AUD and a VND account but decieded to much trouble double dipping as everything I buy or pay for is in VND. So transfer from OZ in VND, exchange rate, which varies between banks is not that bad. The only problem I find with Shinhan is their term deposit is low.
The ability to transfer funds from your home country (in Vietnam đồng) directly to a bank in Vietnam is usually limited by the bank from whence the funds originate in your home country.
Maybe you could add some information about the bank you are using in Australia which is allowing you to wire VND?
Many banks only give the option to send the currency of the home country of the expat (such as USD for Americans) and then often, a physical trip is needed to the bank in Vietnam to exchange that foreign currency into VND and deposit it into the Vietnamese bank account.
That's the way it was for me with one of my accounts at ACB Bank, so it turned out it was better for me to also open a USD account to receive the transfers.
Then I could exchange the money for Vietnam đồng anytime I wanted at a later date
One good way to get around that requirement is if your bank in Vietnam offers an international prepaid debit card account.
I have that at ACB Bank, and when I transfer USD to that card, it is immediately converted to VND and is immediately available (after the transfer/exchange is completed) for using it as a payment card or to withdraw funds from the ATM.
That account was nearly empty when I left Vietnam, and my partner there has the physical card in her possession.
I'm able to wire transfer a very modest amount of funds to that account through my Charles Schwab brokerage account ($15 USD fee) and she can withdraw up to 5 million Vietnam đồng from that account per day through an ATM.
I don't send her much more than that per month, as she is living back on the Family farm in rural Quảng Ngãi.
I also keep the amount I send low because I figure eventually the bank may realize that I am no longer in Vietnam and close that account.
So I don't want to risk sending much more than 5 million Vietnam đồng at a time.
Note: to anyone who would ask why I would wire money to Vietnam when I have a Charles Schwab bank account and get all of my ATM withdrawal fees rebated at the end of the month? It's true I could do that and did do that for my cash needs, but I couldn't then take that cash and deposit it into my standard account at ACB.
The only way I could fund that account was through wire transfer.
I had personal reasons in Vietnam for wanting to be sure I could do that (fund the account).