I know Wally Suarez considered the Madja-as form
N. burkei on the Pitcher Plants forum a few years ago; the original description of
N. burkei is very incomplete, but Jebb and Cheek's old monograph "Skeletal Revision of Nepenthes" (1997) does say that
N. burkei is found on Panay (where Mt. Madja-as is located) and notes that
N. ventricosa is only found on Luzon. The leaf veins are the only non-pitcher feature J&C use to distinguish
N. burkei and
N. ventricosa - the former has 6-7 pairs of longitudinal veins in the lamina while the latter has 3-4. I don't think any recent literature has mentioned the Madja-as form specifically, and I've never personally seen an adult Madja-as plant to compare.
http://pitcherplants.proboards.com/post/109672/thread
Type specimen of
N. burkei is remarkably incomplete:
http://apps.kew.org/herbcat/getImage.do?imageBarcode=K000651451