I haven't found the differences between G. genticulata and G. pellucida but both are called Tahitian bridal veil and are listed as hardiness to USDA Zone 9b to -3,8 degrees C and self seeding so could spread in the ACT. They are sometimes listed as Tradescantia genus.
Steve Taylor, Geoff Butler and myself did an preliminary weed risk assessment of Tahitian Bridal Veil, and determined that it's weed risk was not high enough to justify banning its sale in the ACT, but is one that we will need to be watchful about. Geoff also made the point that horticulturally it is a pretty poor specimen - so why buy it.