Order of bandpass / bandstop filter?
I am unsure if a bandpass with one zero at 0 Hz and two poles above
  would be called a first order or a second order filter.


This picture might help: -



Picture from here.

The orange line is the band-pass response of a 2nd order filter. It has slopes of 20 dB per decade. You might notice that if you rotated the low-pass response anticlockwise it would become the band-pass response. Similarly for the high-pass response.


  the phase approaches +/- 90 degrees, which indicates a first order
  filter.


A first order filter would not have a 180 degree spread in the phase response - it would have a spread of only 90 degrees.