You have just made me realise that apparently I have not made the $3k minimum spend, apparently due to a similar issue. Hence I haven't got my 60,000 bonus points yet. I went back and checked my statement, and figured out that my points earn is less than what you would expect based on my spend of about $3,300 excluding annual fee, and the difference is exactly the same as two utility (gas and electricity) bills that I paid.
I have also gone back and checked the T&Cs, and I agree that there is no mention of utility bills being ineligible for points earn. The T&Cs state:
Eligible Transaction means any purchase excluding (but not limited to) Cash Advances, Balance Transfers, Special Promotions, BPAY payments, purchases of foreign currency and travellers cheques, transactions made in operating a business, payments to other Citi accounts, bank fees and charges such as interest and ATM charges, transactions made using Qantas Points and government related transactions. Government related transactions include transactions with government or semi-government entities, or relating to services provided by or in connection with government (for example but not limited to transactions made at Australia Post, payments to the Australian Taxation Office, council rates, motor registries, tolls, parking stations and meters, fares on public transport, fines and court related costs).
So it seems that utility bills are also not excluded, even though not stated in the T&Cs - personally I don't think that's acceptable, so I plan to call them. This also suggests that any transaction that is not eligible for points earn is also not counted towards the minimum spend.