How does one practice Buddhism when experience is limited by the 6 senses? If one is limited by the senses and the formation of the sense, how does one practice Buddhism which espouses interrelatedness and interconnectedness? 

For example, if i simply taste the grape i have in mouth, how do i realize that the grape is the result of the elements of nature e.g. propagation of seed, pollination, inception of a seedling, sprout, etc which in turn is supported by the sun, rain, soil, etc
If you're eating a grape and you are thinking about the soil and farmers and so on, then you are not eating the grape, you are thinking.  This isn't mindfulness.

You don't try to be interconnected.  You let go of all the conceptualizing that infiltrates experience.  The idea here is that your concepts are the thing that blocks interconnection; let them go, and there's interconnection.  You needn't develop it, you just need to remove the barriers to it.

Ironically, one of those barriers is precisely the exercise you mentioned.  Your thoughts about how you are interconnected to that grape is exactly what's keeping you from really being connected to that grape.

You don't connect in an ecological or social sense, but in an experiential sense.