I ask this question as I'm trying to understand the following statement:   

GEV is based on the sacred Vedic principles of bhakti-yoga. 

http://www.ecovillage.org.in/our-projects#_VEC 

While 'bhakti' is mentioned at least in the above upanishad, I thought 'bhakti yoga' was quite clearly a post-vedic development, and that the bhakti movement developed from the 6th century CE. To the devotee this statement might seem unproblematic, but to the scholar it appears to conceptually and temporally conflate disparate things. 

As I am certainly not an expert on bhakti I would appreciate clarification. 

I am interested in how organisations operationalise the 'vedic' sign in their marketing and promotional material to generate 'authenticity' and legitimacy.