SQL & PL/SQL

Hi,
in my 9.2.0.8 I've got plan like :

Plan
SELECT STATEMENT  CHOOSECost: 26,104  					
	7 TABLE ACCESS BY INDEX ROWID UMOWY Cost: 26,105  Bytes: 41  Cardinality: 1  				
		6 BITMAP CONVERSION TO ROWIDS  			
			5 BITMAP AND  		
				2 BITMAP CONVERSION FROM ROWIDS  	
					1 INDEX RANGE SCAN UMW_PRD_KPD_KOD Cost: 406  Cardinality: 111,930  
				4 BITMAP CONVERSION FROM ROWIDS  	
					3 INDEX RANGE SCAN UMW_PRD_KPR_KOD Cost: 13,191  Cardinality: 111,930  

as far as I know Oracle is trying to combine two indexes , so if I create multicolumn index the plan should be better right ?
Generally all bitmap conversions related to b-tree indexes are trying to combine multiple indexes to deal with or/ index combine operations right ?
And finally what about AND_EQUAL hint is that kind of alternative for that bitmap conversion steps ?
Regards
Greg