That line in your pic goes to the foot brake master cylinder, it's suppose to have brake fluid in it. Follow that line up to the opposite side of the quad & you'll find the fluid reservoir.
For the battery tender hook up, pull the plastic piece under the headlight pod and you'll see a small distribution block with positive & negative from the battery, you can connect to those posts if you want.

 

Turns out the nipple the hose would slide over is broke. Is this a part that can be purchased stand alone? I didn't see it on the rear brake pedal diagram.

Is the bike ok to use without it for now? Was planning a ride for Sunday.

Hooked up the tender connector where you pointed me towards, works great, and hides away nice in compartment when not in use.

 

The nipple is not a separate part - have to but a complete master cylinder

 

I noticed there are two different master cylinders, for built before or after 8/13/13. Does anyone know what's different?

 

Having the VIN and build date would be helpful - but, there were 3 master cylinders available - the models listed with 2 different MC's were all EFI models. The carbureted model used part 1911551. The EFI models used either 1911688 (built on or before 8-12-13) or 1912301 (built on 8-13-13 and later) - both had 1/2" bore and clevis attachment, but 1912301 is listed as 520mm length

 

If you're lucky you might still find a sticker on the rear torsion bar that has the VIN number & build date, that way you know for sure.