The military get's a pass with regards to needing to have prior approval through LOA. Officially, civilian non-RVSM aircraft must precoordinate operations in RVSM airspace prior to filing a flight plan or requesting access (including climbing above RVSM), however there is a lot of lee way given.

Military aircraft in RVSM airspace that don't have appropriate RVSM certified aircraft are subject to normal non-RVSM separation standards (2000' vertical).