It's not politically incorrect, it's a fact. These gambling machines always do better in poorer areas.
Here are some figures from four years back (FY2009) regarding gaming revenues.
LGA or Grouped LGA Aggregate NGR Pop. (Ave) NGR per capita
Adelaide $35,112,065.02 19566 $1,794.54
Norwood Payneham & St Peters $32,446,643.65 35731 $908.08
Port Adelaide Enfield $79,174,176.27 111228 $711.82
Holdfast Bay $24,936,536.76 35513 $702.18
Gawler $13,951,259.40 20600** $677.25
Charles Sturt $65,077,030.42 105547 $616.57
West Torrens $31,105,176.27 55496 $560.49
Salisbury $66,639,042.44 127568 $522.38
Prospect Walkerville $12,940,855.05 28200 $458.90
Playford $32,513,807.23 75544 $430.40
Onkaparinga $64,925,277.71 158022 $410.86
Unley $15,578,147.83 37967 $410.31
Marion $30,384,907.26 83227 $365.08
Mount Barker $10,185,398.28 29031 $350.85
Campbelltown Tea Tree Gully $46,389,163.81 147295 $314.94
Mitcham Burnside $16,157,922.15 108289 $149.21
Adelaide Hills $5,155,977.15 39363 $130.99
**Gawler population an estimate based on current figures at en.wikipedia.org
Not sure what the current figures are but you get the idea.
Obviously there will be some council areas, Adelaide City Council area for example, that bring in a greater proportion of the expenditure from other countries, states and council areas. Conversely, some council areas may be slightly lower as a result.
Any correlation between affluence and gaming revenues - as well as "political correctness" - I'll leave to the discretion of the individual reader.
Sources:-
Aggregate NGR - http://www.olgc.sa.gov.au/gaming/statistics/NetGamblingRevenuegroupedbyLocalGovernmentArea%28Council%29200809.pdf
Population Average - calculated from FY08 and FY09 figures at http://profile.id.com.au (except **)
NGR per capita - calculated from sourced data.