I'm a Clojurian and even though macroexpansion and compilation are well delimited, they are still processed within the same pipeline, namely clojure.lang.Compiler. Lexical scope is determined once and macroexpansion happens progressively, when the compiler stumbled upon expandable forms.
I should have said "build-time state". Anyway I still think the benefits the lisp model of compilation can bring to a language that wants more compile-time computations are not to be found in some mythical homoiconic property of lisps, but in build time state. This allow you to have meta-programming pipelines without the kind of friction this usually requires and that come in the shape of complex build systems that wrap around your compiler rather than living within it.
A form to be compiled is first subject to expansion, and then the expanded result, now devoid of macros is compiled.
Implementations that have multiple modes of processing, such as both a compiler and interpreter, share the macro expander between them.
There is redundancy between macro expansion and compilation. The macro expander has to understand and properly traverse special forms, and build up an environment structure that follow lexical scopes. Then the compiler has to do the same. Of course, the compiler won't have macro content in its environment stacks (lexical macros); those are gone.