I've actually been to a Japanese tea ceremony (In Tokyo) and I didn't even make a connection between the two when I watched the movie. I won't pretend to be an authority on Japanese culture but I think the scene stands on it's own regardless of your knowledge of the wider culture. There are connections between the two but it's really just about the fascination with the intricate details of food. Which is of course a metaphor for the subtleties and complexities of life itself. It's related also to the detail with which Tampopo's noodles and soup are critiqued later in the movie (although to a far less pedantic degree) and what leads to her ultimate success. Brilliant movie!

Juzo Itami was an actor in a hilarious movie called The Family Game, a movie which also made a big deal about food in Japanese culture. I'm betting it had a large influence on him.

It is - as everything else in the movie - a satire. When the old man looks at the slice of pork he murmurs "see you soon".
P.S. the young man is (the now famous) Ken Watanabe in his young days.

Even without any tea ceremony, the scene is funny. The scene appears to religicize (if that's a word) food. Just like many religious ritualize the worship of God/Allah/whatever, the scene has the guru teach the young man the 'religion' of eating ramen. It reads no matter if you understand tea ceremonies or not.