This was my first time in a long time to max out. Now my normal bench press sets are 8-9 at 205 lb.s, 5-6 at 225 lbs., and 2-3 at 235 lbs. I'm looking to gain muscle mass because, hey, it's fun, and I'd like to go up into the 205 weight class for BJJ. I've been lifting for about three and a half years, and in that time, I've added about 30 lbs. of muscle. I can put a lot more muscle on my 6'1" frame before it slows me down; "bulk" isn't an issue until I get above a body weight of about 210 lbs., which won't happen for a long time.
Agent, since you're looking to use your strength in a sport, try using free weights instead of the Smith machine. If you do a normal bench press, that forces you to balance the weight which recruits more muscles - which will make you a stronger player. I know your sport doesn't require great upper body strength (although I know someone who did Ultimate in college and he has equal, if not greater, upper body strength than me), but if you're going to do strength training for it, then you might as well get the most out of it. I used a Smith machine for bench press for a while, and when I switched to a normal bench press, I had to decrease the weight because I wasn't used to maintaining control of the bar.
Seeker, do you mean you do bench press with 100 <i>pounds</i> or did you really mean 100 <i>kilograms</i>? At your height and body weight, 100 lbs. doesn't seem like it would do much.
Anyway, in general, regular exercise is good. Find something you enjoy and keep doing it, as it significantly improves quality of life.