this could have changed as I haven't used Diners for a long time.
Firstly, of course, it's 2 points per dollar and these are all shown as Bonus points on the statement.
Regrettably, Citi recently announced major changes to its points scheme as applied to it's Premier Card (MasterCard) customers. These changes also impact companion Diners Card holders.
Until recently, Citi offered bonus points for transactions at major retailers such as petrol stations & supermarkets (1.5 points)/$1, with companion Diners cards scoring 2 points/$1 at these retailers), while spend at airlines, hotels and restaurants received 2 points/$1 on both the Premier MasterCard and the Companion Diners. Standard points for other transactions were 1point/$1.
Alas, the bonus points are no longer offered.
Instead, it's now a standard 1 point/$ for all eligible transactions (ie non-govt transactions - ineligible transactions are govt, which includes Australia Post, ATO, State Govt public transport, council rates etc. BPay transactions are also excluded from collecting points). The only exceptions to the 1 point/$ rate are online transactions (but not PayPal etc) and overseas transactions, which both attract double points.
Companion Diners cards now receive the same points earn as the MasterCard - so there's no longer a points benefit when using the Diners companion card.
Citi Qantas Rewards program customers with the Premier MasterCard score half the points discussed above, in the form of Qantas points. So in general, eligible transactions now score 1/2 Qantas point per $1 spent and 1 QF point/$1 for online and overseas transactions. No other bonuses.
So unless a Citi Premier customer's main spend is online, the new scheme is clearly a downgrade.
Welcome to discount economy, folks!