You really don't understand how these things work.
First of all, Bonner's contract doesn't end in January. It's not currently guaranteed past January, but if he's not waived by January 7th, it will become guaranteed for the remainder of the season.
So, the Spurs set up Bonner's contract in such a way that it can be used as part of a trade package or so that he can be waived to create a roster spot. All of which has nothing to do with Cady.
While there is a less than remote possibility that Bonner is waived to create a roster spot, there is almost zero chance that he's waived to make room for Lalanne.
Here's why:
1. Lalanne is a second round pick.
2. The Spurs are over the cap.
3. The only exception the Spurs can use to sign Lalanne this season is the minimum salary exception.
4. The maximum length of a minimum contract is two years. Signing him this year would make him a free agent at the end of the 2016-17 season.
5. If they wait until the summer to sign him, they can use a small chuck of cap space or the MLE, depending on their cap situation, to sign him for a contract of up to 4 years.
6. The only scenario that has the Spurs signing Lalanne this season is one in which they're convinced that he can replace Diaw or West in the rotation. That's possible is the same sort of way that discovering bigfoot is possible.
7. So forget about Lalanne on the Spurs this season.
8. Good luck with your wish to see Ray waived. That's extremely unlikely as well.