The lump sum you should be able to do what you like with. Either you leave it in a UK bank account, or you make arrangements to transfer it to an Australian bank account, transferring at the prevailing exchange rate at the time.
If you leave it in the UK, tax at 20% gets deducted at source. Don't know how Australia taxes its unearned income.
I would taks to the trustees of your occupational scheme to see what they advise.
IAP's point is interesting. IAP - do you have to prove residency in the UK to benefit from annual increases in value of Basic State Pension? Can you not have the money paid into a UK bank account as if you ARE based here? - then withdraw sums from Australia?
Rock - beware of long-term impacts on your pension value from erosion of the value of the � against the Aussie dollar - which of course could go either way in future.