Not all Amazon Instant Video movies available on TiVo?

Was interested in the a documentary titled, "Cavedigger" about a guy who digs out and then sculpts caves in the Santa Fe area:



http://ift.tt/1zHLi31



Did a search on my Premiere and did not find it. However, did find it available on Amazon Instant Video online via my computer and my iPhone for $3.99.



Does TiVo not have access to the complete catalog?