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Yes, you will weigh more when you have more muscle, compared to having less muscle (but the same amount of body fat). More muscle is generally healthier. Note that muscle is dense, so it can significantly increase your weight even though it may not look like much.

Body weight is really not the best way of setting fat loss goals as one gets closer to the "healthy weight range". Body fat percentage is better, since those heavy with muscle could have a healthy (low, but not too low) body fat percentage, while those within what is usually called the "healthy weight range" may have a high body fat percentage that indicates increased health risks. However, measuring body fat percentage is at best an approximation; the more accurate methods (involving underwater weighing or dual energy x-ray analysis) are less convenient and more expensive than less accurate methods (skinfold pinches, electrical resistance scales, formulae based on various measurements like waist size).

Perhaps a simple to measure means of setting a fat loss goal would be to try to get your waistline to be less than half your height, and less than 0.8 of your hip (for women; 0.95 for men). Athletes may have smaller waistlines, perhaps down to 0.45 of their height (though it depends on the sport).