Unlikely, I don't think we have any P pandorana on the site. we have wombat berry (which has emerged strongly), garden Jasmine as weed, asparagus fern, kennedia, and a hibbertia, which hasn't reappeared yet. This plant looks like it to going to be shrubby. Will take more pics as it gets bigger.
It would be good to see a photo of the flower Lyndal. I must have suggested Pseuderanthemum variabile, Pastel Flower in the first instance, before I lost faith? If you copy that name into 'search', there are a few shown. Thanks for the feedback!