I think re: pantheism Dawkins has in mind something like Spinoza's "God or Nature", the sort of idea of the divine which Einstein said he could believe in. And I think the idea is that it is the kind of conclusion (in Spinoza's case, this doesn't necessary apply as well to something like a demythologized advaita) that is reached from premises that are more naturalistic, and so it is kind of naturalistic (read "atheist") view that deifies that nature.
On the other hand, deism in practice tended to begin with the worldview of something more like the Abrahamic traditions, hence the idea of the deistic God as a creator, but retreated from the claims of those traditions which can't be justified rationally or be reconciled with science, i.e the supernatural claims.