Best Credit card for rewards points and signup bonus offers?

is the highest-earning card in Australia if you're chasing SQ KrisFlyer miles on everyday spend (the only exception being the AMEX Business Accelerator on spends less than $50k per year), and is in equal first place for Velocity points too - same ultimate earn rate as the AMEX Velocity Platinum, if not actually better because you can hoard points and then convert them when Velocity has one of its 15% transfer bonuses running.

The Explorer can also convert points across to Cathay Pacific Asia Miles, which allows you to book Qantas and Oneworld flights if you so wish (ditto via Malaysia Airlines Enrich but for more points), and you can convert points to Emirates too which can again be used for Qantas, plus Emirates, Korean Air, JAL and a few other sweet spots.

Etihad Guest is also a great transfer partner because you can use Etihad miles to book Virgin Australia flights, and you often need less of those miles compared to Velocity to book the same thing (Sydney-Melbourne is 6,900 Etihad miles in economy or 13,800 in business, whereas Velocity is 7,800 points for the same or 15,600 in business).

AMEX doesn't highlight this very well, but you can also convert points 1:1 to Hilton Honors and 2:1 to SPG.

Other transfer partners include Air NZ Airpoints and Thai Airways ROP, so it's a very flexible card. :)