It'd be slightly useful if any part of it was correct.
As mentioned above, your walking call will be made no matter the outcome of your if statement, and your if statement as it stands currently checks if you're in the bank and your inventory contains rune essence OR your inventory contains pure essence, with no bank check.
The correct code would be:
if (Banks.FALADOR_EAST.contains(myPlayer()) && (getInventory().contains("Rune essence") || getInventory().contains("Pure essence"))) {
// walk
}
although, you could just simplify it to:
if (Banks.FALADOR_EAST.contains(myPlayer()) && getInventory().contains("Rune essence", "Pure essence")) {
// walk
}