Not so much.
Banks can't credit funds to anyone's account that they do not have in their own.
If we could create money at will we could have avoided the credit squeeze
When I have thought through this it would seem that the bank can (if they were stupid) create deposits at will. This of course would send them broke however in time as they are basically giving away their own capital. I guess like anyone you can promise to pay someone in future without having the funds to back it. What they are incapable of doing is creating loan assets without funds to give to these people as who signs up to the bank for a loan if you get nothing for it? This is what they are in business to do; create loan assets and to do this as you say they need funds.
So they can unilaterally create funds in a depositors account assuming the depositor does not draw them down but there is no benefit to the bank in doing this, indeed they are just giving money away. However with borrowers there is a reason they want the loan and this is to buy something and in order to settle on this thing they need funds to do it.
One example someone gave me to show me loans do not always have to be funded is when a person applies for a loan and puts it in a deposit account at the same bank. As I see this transaction the crazy borrower is funding his own loan and this really is not a likely real life scenario but still even in this the borrower funds his own loan not the bank.
Whatever way you look at it to create loan assets the bank need funding whether it be from the seller of an asset, offshore, their own capital, from somewhere they need funding.
For clarity however this is not to say banks through loose lending do not create an increase in Australian M3 due to higher asset sale prices achieved. There is another side to the ledger of borrowers and this is sellers / depositors and of course if banks loose lending sees asset prices rise there is going to be some increase in deposits. It would seem in Australia our increase in deposits has not been enough to fuel the fires of our credit requirements.
So I can see that banks can through various policies create M3 money indirectly, but importantly this does not mean they can do it at will and unilaterally with borrowers only. They still need both depositors and borrowers to do it by increasing funds and lending them out and hoping a lot of the new lending comes back to them as deposits to enable them to do another round etc just like the multiplier effect...