VGFacts

All of the songs on the radio station, Flashback 95.6 in GTA III, are all from the Scarface soundtrack.
Push It To The Limit-Paul Engemann
Rush Rush-Debbie Harry
She's on Fire-Amy Holland
Shake It Up-Elizabeth Daily
I'm Hot Tonight-Elizabeth Daily

http://en.wikipedia.org/wiki/Scarface_%28soundtrack%29
http://en.wikipedia.org/wiki/Grand_Theft...soundtrack
Is this significant trivia?

Well that's an intersting bit of trivia !

Would this be classified as an easter egg?

Trivia and Easter Egg often have blurry boundaries... I'd go more towards Trivia as it's a fun fact rather than something you find in the game and go 'oh will you look at that!'.

Good job. I've had the game for years, known that for years, and still did not check to see if it had been submitted.