Depends on your diet and how long you train for.
If by "bulk" you mean weight than it will fluctuate regularly but it is really a matter of calories in and calories out.
If by "bulk" you mean strength, then in order to maintain it, just do a set of heavy weights per body part per week.
Either way, you can monitor both (strength and weight) and make your adjustments accordingly, but don't make the mistake of worrying to much about it while training or your will not be focused your training and it will suffer.
