How do I tile across two different wall materials?
Easy peasy. Looks like there is a slight depth difference from concrete to plywood—not a problem. 

Encapsulate existing plywood with 1/4” Hardibacker or other cementitious backboard using 2 1/4” galvanized roofing nails at all designated points. At the seam with the concrete, use fiberglass backer board tape and the same Thinset you use to set the tiles. You can set the new tile directly to the existing concrete as long as it’s smooth. If not, a skimcoat of Thinset mortar will even it out. If the difference is greater than 1/4” use 1/2” Hardibacker. 

Use 1/4” Hardibacker and cover the plywood only. You have several options for the concrete. You could set stone tile or river rocks; many options. Since you want to go floor-to-ceiling with the new tile, for visual interest set a larger, thicker tile on the concrete as a “baseboard.” This base tile should be approximately 1/2” thick lug-back tile (or stone, etc.) which will meet the bottom edge of the hardibacker a quarter of an inch out. For wall tile, easiest installation is 1/4” thick, talc-back tiles.

If you post a photo of a design you’ve seen and want to use as inspiration, I’ll give directions on that particular installation process. Here’s an example of a tiled wall with a base different from the rest of the wall. 



Post photos after your project is completed. Good luck!