Are BIP 100, 101 and 102 being voted on now by Bitcoin miners? Are the BIP 100, BIP 101 and BIP 102 proposals being voted on now by miners? What is the procedure for a bitcoin miner to vote for a particular BIP and where can a tally of votes be viewed?
There isn't any blockchain voting for accepting a BIP: See How is a BIP accepted? and BIP0001.

Rather, the BIP is accepted or rejected on the basis of consensus. Consensus is never defined, but even if you interpret it fairly broadly, I don't think any of the three will reach consensus.

There are frequently blockchain votes about activating the new rules, but that's less of a mechanism to measure acceptance and more of a way to only deploy the new changes once enough of the network runs them that the switchover won't be disruptive.

There is a related issue, which is Bitcoin-XT, which grew out of several developer's frustrations with the process. That proposes to alter the blocksize according to BIP 101 once more than 75% of the blocks are created by Bitcoin-XT nodes. But that's not something within the BIP process.