I ripped my DVD-A discs so long ago I'm not going to immediately remember all of the details, but one thing is for sure, I never tried to rip the DTS layer of those discs.
Nor do I understand why anyone would, but that probably also reveals my ignorance towards most things surround sound. I couldn't begin to guess what combination of software player and hardware playback system is needed for DTS compatibility.
That said, I have the Bonnie Raitt titles on DVD-Audio and the stereo tracks certainly ripped just fine, I assume we are talking about the very same discs and not some special limited release for DTS (I know those were a thing at some point in the past). Many of those are not actually DVDs, some are DTS-CDs. The only examples I have of DTS-only DVDs I bought by mistake many years ago, didn't look carefully enough at the labeling, they were not really DVD-Audio, but DTS-DVD that doesn't play in anything except a DVD player with an onboard DTS decoder.
Which title are you trying to rip and are you sure it is a DVD-Audio?
I unearthed my DTS-DVD-Audio discs, sorta irked me all over again how some of these were marked and marketed, very misleading.
Of the 3 discs below, only one has rip-able stereo tracks (the Frank Zappa Halloween disc), and even there, the 24/96 labeling is only "Advanced Surround DTS". The stereo tracks I ripped are 24-bit 48kHz PCM.
The other two, those were my fault while on some drunken sailor disc buying binge at the now defunct Circuit City. They are marked as DTS-only but I failed to take heed and thus they were and are to this day useless to me. Because it was really my fault, I didn't return them.
On the Zappa disc you can see why only the 24/48 was rip-able, the compatibility chart (which conveniently only appears on the inside booklet so you wouldn't know this until opening the packaging) clearly states that DVD-ROM drive compatibility (read: Computer) is not available for the Advanced Surround content. Those other two DTS-only discs are thus not rip-able, the computer's DVD-ROM drive won't recognize them, only a DTS capable DVD player will, and there is no stereo PCM content on them at all.
Is your Bonnie Raitt disc actually a DVD-Audio, or is it some weird DTS disc like the above?