I've been doing this full body routine and it's been working great -Ive increased my bench from 6 x 225 to 6 x 260. But I've plateaued at 260. should I go down in weight and work my way up or should I increase weight and decrease the reps and then try to go to 265
Vary the reps first. If you were training in the 6 - 8 try 3-4 or 10-12.
If that doesn't work I'd try dumbells.
Both approaches can work. Decide based on how you feel and how long have you alredy been able to progress.
For instance, if you feel great and ready to train, try doing 5-6x3. Use 260 for the first workout, so you get a bit of a break, and then increase by 5lbs per workout, as long as you can.
However, if you feel fatigued and weight seem to feel heavier than usual, and you have to mentally push yourself through a workout, then cycling back would be better, in my opinion. Something like this: 235, 245, 255, 265(PR)...
I don't know if you bench twice a week, but if you do, here is something you might want to try.
Workout A (work capacity)
Work up to your 6RM for the day. From there you continue to do sets of 6 with 15 pounds less than your 6RM. Go until you cannot do a set of 6
1- 265 x 6
2- 250 x 6
3- 250 x 6
4- 250 x 6
5- 250 x 6
6- 250 x 6
7- 250 x 5 (you're done)
You can do that for any bench variation (flat, close-grip, incline, dumbell).
The do whatever other work you do, I would try to keep the volume/intensity a little lower than normal though because you are trying to focus on the bench.
Workout B (performance)
This is a little simpler. Work up to your 6RM for the day. Resting 3 minutes in between sets, continue to do sets with that weight until you can only complete 4 repetitions. So it might look like this:
265 x 6
265 x 6
265 x 5
265 x 4 (you're done)
And then do your normal workout, again with slightly less volume and intensity.
If you go three days a week, just alternate workouts. I bet after 6 of those workouts you'll be able to get 275 for 6 reps.