When can a taxpayer claim the tertiary tax rebate?

If a taxpayer turns 75 after 1 March 2017, does he/she get the benefit of the tertiary rebate in the February 2018 tax year, and does he/she have to already be 75 at the start of the tax year which would mean he/she can only get the rebate in the 2019 tax year?

Yes, the law is that if you are the age by the end of the tax season then you get the rebate in that season.