Of course, as I wrote before, if they hear your accent and know that you have come from America, then of course they will expect a tip as they know of your tipping culture.
Luckily down here, all the cruise ships that sail from an Australia port and cruise back to an Australian port have stopped taking out the daily gratuities. Whether they are now included in our fare, I have no idea but it is a much better way of cruising. We have always handed out envelopes to those we think deserve them on the last day. Mainly to our wait staff in the dining room and our room steward.
As far as tipping the bus driver when on a tour. We have travelled extensively in the States and often we have found we have been the only ones to give the driver and guide a tip and we were probably the only Aussies on the bus. I have watched the passengers getting off as quickly as possible through the rear door! Here in Australia, no-one has to tip and the tips are not expected. We follow your custom when in the States and in the countries that expect tips, so please do not force your custom of tipping here in Australia. Surely that is the end of the argument which apparently has been resurrected from 2008!
2017 Sea Princess Sydney to Sydney via Hawaii, Tahiti & New Zealand
2017 Emerald Princess Sydney to New Caledonia & Vanuatu
2016 QM2 - New York to Southampton
2016 Marina - Papeete to New York
2016 Golden Princess Melbourne to New Zealand & Return
2015 Sun Princess - Brisbane to New Guinea
2015 Ocean Princess - Singapore to Cape Town
2015 Celebrity's Solstice - Sydney to New Caledonia & Vanuatu
2014 Diamond Princess - Kyushu & Onsens Mystery Cruise around Japan due to 2 typhoons
2014 Ocean Princess - Australia & Asia
2013 Noordam - Adriatic & Roman Explorer
2013 Ocean Princess - Land of the Midnight Sun
2013 Celebrity's Solstice - Auckland to Sydney
2012 Emerald Princess - New England Cruise Tour
2011 Royal Princess - Tahiti to Ft. Lauderdale via Sth America - Farewell Cruise
2010 Ocean Princess - Capetown to Dover - via West Africa
2009 Prinsendam - Athens to Ft. Lauderdale - Transatlantic
2009 Azamara's Quest - Hong Kong to Beijing - Far East Asia
2008 Tahitian Princess - Vancouver - Vancouver - Alaska in depth
2008 Oceania's Nautica - Hong Kong to Athens - the Pirate run!
2007 Tahitian Princess - Tahiti to Hawaii
2007 Pacific Princess - Sydney - Sydney - the Pacific Islands
2006 Veendam - Vancouver to Tampa via the Amazon
2006 Galapagos Explorer ll - Galapagos Islands
2006 Regal Princess - Rio de Janeiro to Valpariso via Antarctica
2005 Maasdam - Boston to Rotterdam via Greenland, Iceland & Norway
2004 Prinsendam - Athens to Venice via the Black Sea
2004 Tahitian Princess - Tahiti & the Cook Islands
2003 Noordam - Copenhagen to Rome
1999 Maasdam - Dover to Copenhagen via Russia (Baltic)
1995 Olympic - Greek Islands & Istanbul
1982 Oriana - Pacific Islands & New Zealand.
September, 2017 - Scenic River Cruise - France 21 days
December 2017 - Southern Cross Explorer - Oceania's Regatta - 34 days