scroll down to the bottom of SW home page: https://www.southwest.com/?clk=GNAVHOMELOGO
or you can click here: https://creditcards.chase.com/a1/...PMEM171019
This is copied from the terms:
If Companion Pass is earned by flying 100 qualifying one-way flights or earning 110,000 qualifying points in the calendar year while qualified for promotional Companion Pass through December 31, 2018, the regular Companion Pass qualifications will supersede the promotional Companion Pass, entitling the individual to Companion Pass through December 31, 2019.
So you try out CP for 2018, if you like it, get another SW card and work on hitting 110K points. You can then get CP through 2019!