  Bilayer graphene samples may exhibit regions where the two layers are locally
delaminated forming a so-called quantum blister in the graphene sheet. Electron
and hole states can be confined in this graphene quantum blisters (GQB) by
applying a global electrostatic bias. We scrutinize the electronic properties
of these confined states under the variation of interlayer bias, coupling, and
blister's size. The spectra display strong anti-crossings due to the coupling
of the confined states on upper and lower layers inside the blister. These
spectra are layer localized where the respective confined states reside on
either layer or equally distributed. For finite angular momentum, this layer
localization can be at the edge of the blister and corresponds to degenerate
modes of opposite momenta. Furthermore, the energy levels in GQB exhibit
electron-hole symmetry that is sensitive to the electrostatic bias. Finally, we
demonstrate that confinement in GQB persists even in the presence of a
variation in the inter-layer coupling.
