In situation A) there is no mention of growth, so there is no reason to assume something is cultured. If we assume that in A) a germ plant arises, it is no tissue culture but a regularly bred plant. It is no tissue culture, because a seed is typically formed after pollination, which involves the recombination of parent genes to form reproductive cells (pollen) and the fusion of these reproductive cells after pollination. Because the definition of plant tissue culture is:
"... a form of cloning in which the plants are all genetically the same - similar to taking cuttings." (quoted from: Royal botanical gardens, NSW, australia).
it follows that seedlings are not clones of their parents.
Situation B) therefore meets the criterion of tissue culture, as new tissue grows out of a single progenitor cell.
So the answer is: they are not 2 examples of tissue culture, the difference being that A) is the result of a normal breeding and B) meets the criteria of tissue culture.