Wirelessly posted (BlackBerry9000/4.6.0.282 Profile/MIDP-2.0 Configuration/CLDC-1.1 VendorID/102)
I believe that up until sometime in 2006 purchasing a Y/B fare did automatically entitle you to an E+ seat. However, that program ended with introduction (or in preparation for the introduction) of being able to purchase E+ as an upgrade and also purchase E+ access for a year.