Hi Alvin,
Like the look of #155. I believe the dark blue line is not needed to boldly make the ying and yang look. I think the color gradient and the nice bend you made with the jellyfish give us that look. Please try it without the line and let us see what that change does.
#154 looks okay. like 155 more. The new slogan reads nice, too.
You are doing a good job.
Thanks!!!