The 20-year-old had found it difficult to choose between the two sports since she started making Otago teams in secondary school, but the lure of the Beijing Olympics in China next month proved too great.
"I had a few tough decisions, but they have all seemed to work out in the end," Bates said.
"So I'm pretty happy about it all.
"I don't know if it has really sunk in yet. It has been a long process, but finally we know."
There were some mixed emotions as well - her Otago teammate Toni Edmondson missed the cut.
"We knew it was close and it could have easily been me. So I was definitely feeling for Toni knowing she has put in just as much hard work as I have."
Bates shifted to Christchurch last year to play for the Christchurch Sirens and decided to stay there to push her Olympic prospects.
The Tall Ferns open their campaign against Mali on August 9 before further group B games against hosts China, world No 1 US and European powers Spain and the Czech Republic.
"We've targeted the first two games over there against Mali and Spain as games we think we can win.
"We need to win two to go through to the next round. That's the goal and from there we'll reassess."
While basketball is Bates' sole focus, she hinted that come summer she might be ready to swap the hardwood for a cricket pitch.
"I've always said after August I'll reassess. If I think I can give it a good go, I'll put the cricket pads back on and see how it goes."
The Tall Ferns leave for Beijing on July 30.
