Lua's designers have acknowledged a lot of Scheme influence, especially from 4.0 onward, but I think it's more about the semantics than the implementation.

Lua uses a type tag + union rather than tagged pointers because it's not strictly portable, and they've placed a high priority on strict ANSI C compliance (with the sole exception of dynamic library loading). Also, Lua tables recognize when they're being used as arrays and use an array internally.