Yes.
However, to withdraw deposited BNT from a pool, you must have the same number of vBNT in your wallet that you would like to withdraw, though not necessarily the same vBNT tokens you first received.
In other words, you can trade your vBNT for other tokens or send it to a different wallet while your BNT is deposited , and buy vBNT back if/when you want to withdraw your BNT from Bancor.
Only your wallet can withdraw your deposited BNT using the necessary number of vBNT. Make sure you understand the risks of trading your vBNT before doing so.