Melvyn – Dom is slightly mistaken on the pre-1811 organisation.
From 1811, like most Confederation of the Rhine contingents, the Bavarians did indeed adopt the standard six-company (grenadier, light and four fusilier) French organisation for both their Line and Light battalions. Before that, both types had five-company battalions (one grenadier and four fusilier for the Line, five fusilier for the Light), but you should note that one fusilier company in each case was the depot company and did not take the field with the battalion*. Thus, in the field, both Line and Light battalions had four companies of 180 rank-and-file each – so very large companies.
[* Naturally, there was an exception. In the 1809 campaign, each of the three Bavarian divisional commanders had an "etat major" (a kind of close protection unit for the battlefield) comprising a "division" of two infantry companies, and a "division" of two cavalry squadrons. Both divisions were composed of the depot units of one regiment. ]
In the field, each field company in a battalion (including the grenadiers of the Line battalions), contributed 36 schutzen, of whom 7 were armed with rifles. The combined schutzen of all four companies could sometimes be detached from the battalion as an avante-garde, or any skirmishing task. In Line regiments, the schutzen of both battalions frequently worked together, and on occasion also with the detachments of the other regiment in a Line brigade.
When away from the enemy, the men would return to their parent companies on the march, but if the battalion remained in contact with the enemy they would stay "converged" and, in effect, a battalion (Line or Light) would have five companies of 144 men, rather than four of 180. That said, only four companies would stand/manoeuvre in line, with the schutzen "company" either to the rear or protecting a flank.
Thanks to the influence of an American Loyalist, Count Rumford, the Bavarians – at least until they had been allied to the French for a while – operated almost in a British style, in two ranks rather than three. In 1809, the French tried to influence a change, but the deployment of schutzen allowed them to revert to two in the field until the end of the Danube campaign. From 1811, of course, they were left with no choice.