You're wasting your money with the bathmate. A cheap $20 USD penis pump tube from amazon.com and a brake bleeder vacuum pump (mityvac) from your local auto parts store for $25 USD is much more usable. For a "boot" or seal at the bottom of the tube I use a 4 inch piece of rubber bicycle inner tube. Stretch the rubber over the end of the plastic penis pump, wrap with vinyl electrical tape to seal and fold inside the tube. Makes a very comfortable seal.
As far as wrapping while pumping I've tried various types of wraps. Ace bandages tend to stick to the rubber seal when entering the tube. This makes insertion difficult and the bandage tends to slide off. I've also tried the rubber elastic athletic handle covers, it's a padded rubber tube designed to slide over the handle of a tennis racket or something similar. These might work okay for other guys, but they're a bit on the small size for me and uncomfortable/painful. I've also tried self sealing rubber tape. It's used as a wrap around leaks to seal them quickly. This works pretty good as you can customize the size to fit you although I find I slip out the top and a donut forms where the soft skin just below the penis head swells too much.
For me the best wrap while pumping has been condoms. You can layer them to increase the constriction to the level that you like. I find non-latex condoms work best. I cut the nipple off the top of the condom with a pair of scissors leaving a very small hole, approximately 1/2 an inch. I put the condom on as normal and stretch the top over the head, rolling down a few rolls before securing it below the ridge of the glans. I usually use two when doing this. The small hole in the condom creates a natural ring as it's stretched and rolled down which helps secure it in place. If you cut the hole too big you'll find the condom will slide down, especially as you pump and the skin behind the glans tries to expand and form a donut. If the condom does slide down the resulting donut is more pronounced and more painful.
An additional trick i've used is to use gel super glue to secure the condom in place and keep it from sliding down while pumping. I use a single dot on the frenulum, the underside of the penis just below the ridge. The superglue readily sticks to the condom. With the swelling and movement from pumping and with a bit of warm water the superglue will come loose easily. It's important to not use too little as a very thin layer bonds much more strongly than a thicker spot. I use a drop about 1/4 to 1/2 an inch in size.
Wrapping while pumping certainly increases the pressure on the head. After about an hour though I find I'm _much_ more likely to be at risk for pressure blisters. It's important to stay under 6mmHg, which is why having a pump with a pressure gauge is vital.
I'd be interested to hear how other's fair with pumping while wrapping with a condom.
Have fun and be good to yourself.
