Most suburbs have entrenched competition. Businesses have been ranking for years. Breaking through is hard.
Tarneit is different. The market is still forming. Many local businesses haven't invested in SEO yet — they're relying on word of mouth in a suburb where most residents are new and don't know anyone.
This creates a window. Businesses that establish strong local rankings now will benefit for years as the population continues growing. Those who wait will face much stiffer competition later.
The time to build your presence in Tarneit search results is before everyone else catches on.