I’m not a coach but I have done both yoga and cycling and recorded the TSS values. It all counts towards fitness, but depending on your fitness level and goals some activities just count, and help, more than others.
Somewhere on this site there is advice to count cycling as 1/3-1/2 the “recorded” TSS, which is what I did when I was bike commuting a lot. For about a week I wore a HR monitor on my commute and recorded 1/3 the HR TSS value that Training Peaks gave me. After that week I stopped wearing the monitor and just recorded the TSS manually because it was really consistent.
For Vinyasa Yoga, I have used 20TSS/hr because some of the poses seemed to give a general strength effect, but not significant. This one seems more like a more individualized TSS would be best.
Others might have a different approach, but that’s what worked for me.