In the following sentence, taken from an article about tatami the transitive and passive verbs (編む＆作る）seem to be combined into one phrase to express what I have said translation but it does not seem to fit any logical grammatical sequence:
Tatami-omote is the surface of the tatami mat, in other words the part that comes into contact with people's feet. It is made from rushes woven together.
I assume the Japanese (if not my translation) is correct but can somebody explain the logic of what is being described grammatically?
My best guess is that the passive verb （作られている） is somehow acting on the transitive (編んで） in the same way that ある acts on transitive verbs in expressions such as 「ご飯を作ってあります」(note) but it is my first time to see this and I don't recall it in any text book.
Note: を was chosen deliberately in this example to be consistent with my subject sentence.