Hello my dear, After applying for partner visa 309, its difficult to get visitors visa. My wife applied for partner visa on Oct, 2017 and up till now she has not be granted. I have applied for visitors visa 3 times but was rejected. Just last month (after 19 months) the CO requested for further information (my pcc and wife's pcc, bills etc). These days its very difficult to get visitor visa approved. I think its advisable to go thru immigration lawyers
good luck