There is no cause for concern if the "glass" pattern is visible through the topcoat. In fact we actively encourage our Approved Contractors to put the Topcoat on thinly so that the pattern is visible.
WHY? We don't want to hide anything. The topcoat is decorative, whilst the base coat reinforced with the chop strand mat, provides the strength of the laminate.
If we can see the glass pattern we know that the laminate has been correctly installed and consolidated thus excluding all air from the laminate. The recommended thickness of the topcoat should be within 0.25 and 0.50mm