  This paper presents a milliarcsecond-scale comparison of the polarised
component-level v=1 J=1-0, v=2 J=1-0 and v=1 J=2-1 SiO maser emission toward
the supergiant star VY CMa. These observations used the VLBA at {\lambda}=7mm
and {\lambda}=3mm over two epochs. The goal is to use the relative
characteristics and spatial distribution of the transitions in individual
resolved maser components to provide observational constraints on SiO maser
excitation and pumping models. We find that many v=1 J=1-0 and v=2 J=1-0
features overlap in the second observing epoch, at comparable sensitivity. The
v=2 J=1-0 emission is primarily located within several v=1 J=1-0 regions, and
has a high degree of morphological similarity in the northeastern envelope,
supportive of local collisional pumping. We find significantly higher spatial
overlap between v=1 J=1-0 and J=2-1 features than generally previously
reported. However, the overlapping v=1 J=2-1 emission is usually weaker than
predicted by hydrodynamical models, possibly due to low-density collisional
pumping. The overall maser morphology contains several large-scale features
that are persistent over multiple years and are likely associated with
intrinsic physical circumstellar conditions. Our data cannot distinguish
between competing near-circumstellar bulk kinematic models but do provide
evidence for localized inhomogeneous mass-loss.
