I don't think the comparison apply in this way, Turing machine may operate on an unconstrained tape but they only look at a single cell at each step.
This find and replace technique operate on a bounded context but, in the same way as a turing machine, they can "technically" operate on an unconstrained tape (technically here because the find transformer wouldn't be able to lookup an infinite tape in the real world).
I guess you could say that a turing machine has a bounded input length of 1.