That’s not strictly the case. In general, * and *~ just mean binding and unbinding. The particular algebra that it uses (e.g., circular convolution, versus VTB) depends on what algebra is passed to the Vocabulary that is being transformed. See: nengo_spa.vocabulary — NengoSPA 2.0.1.dev0 docs
In particular, there is an algebra parameter that defaults to HRRs (circular convolution), but can also be nengo_spa.algebras.VtbAlgebra or even your own custom algebra.
See this example in the user guide for a demonstration of how a Vocabulary object can be initialized using the VTB algebra: This page has moved