Thank you Telstra & Boost! After seeing this post https://www.ozbargain.com.au/node/524638 from Twix I thought i'd try entering my Boost pre-paid mobile number (and my wife's too) to see if Telstra were also giving bonus data to Boost customers. We are on the $150 plan and both received a text this afternoon saying "Your 10GB bonus data to use within Australia has been added to your service." It has also appeared on my My Boost account as Bonus Data at the bottom of the My Boost page & the expiry for mine says 17/4.
Try this link if you are having troubles https://say.telstra.com.au/customer/general/forms/COVID-19
The previous post said Boost wasn't included so I thought this deserved a post of it's own even though the link is the same, but feel free to remove this mods if you don't think it does.