given the importance placed on family lineage in their culture
Just out of curiosity, what importance?
In the two Vulcan families we followed up close, Spock's and T'Pol's, estrangement was the word of the day. Tuvok's family tried to remain close-knit across the galaxy, but there was never any stuff on grandparents or ancestors, nor mention of family traditions.
Spock's folks had ancestral ceremonial grounds, but how is that a "lineage" thing? Apparently they cross-married on those grounds regardless of lineages, sometimes even with alien animal women from outer space.
Put short, I don't get an impression of "ancestor worship" or even "lineage respect" in the canonical or even the common novelized appearances of Vulcans. These logical and superstition-free folks tend to be self-made men and women to a large degree, and they actually view tradition with embarrassment and disdain... And I don't think any one of them has ever spoken highly of a preceding generation. Surak worship is something universal to the modern Vulcan, not something specific to Spock's bloodline.
Timo Saloniemi