A print journalist by training, Tomalaris got his break in television in 1987 when Les Murray asked him to provide commentary for a National Soccer League match.
[citation needed] Tomalaris joined SBS full-time in 1992 and became a recognised commentator of matches involving the NSL, Socceroos and Olyroos.
He went on to work as a reporter/commentator for SBS at the 1992 and 1996 UEFA European Football Championship and the 1994, 1998, 2002, 2006 and 2010 FIFA World Cup, and was known for developing the network's Tour de France coverage.
In July 2011, SBS enjoyed record viewing numbers as a result of Cadel Evans becoming the first Australian to win the Tour de France.
Tomalaris instigated and supported an annual charity bicycle ride, The Johnny Warren Jamberoo Classic, in honour of his former colleague and Socceroos captain Johnny Warren (1943–2004) to raise funds for Chris O'Brien's Lifehouse at Sydney's Royal Prince Alfred Hospital.