You are welcome to withdraw your money out of your Bidvest Bank Investment Account at any time, provided the funds have settled (Ie. if you are expecting them from the sale of an investment), and are not locked up (ie. as a result of being deposited by debit order or from the redemption of a marketing / promotional voucher).
To determine what amount you can withdraw to your bank account, you need to consult the "Withdrawable funds" amount displayed on the red Bidvest Bank Easy Equities 'card' on the homepage of your Bidvest Bank portal - see image below.
For full details - consult this FAQ article - How do I withdraw funds from a Bidvest Bank Investment Account?
Due to the integration between your Bidvest Bank Grow Account and your Bidvest Bank Investment Account, the transfer of withdrawable funds to your Bank account should be almost immediate.