The main advantage of having them slabbed is increased buyer confidence, which, yes, may draw in bids from some buyers who are willing to pay a premium for slabbed pieces
However,
1. Slabbing world coins is somewhat expensive.
2. There is a considerable price jump from circulated grades to UNC.
3. Both of your pieces appear to be cleaned, and as such are at risk of being "bodybagged" if sent to PCGS.
As gxseries hinted at, high circulated grade Kwangtung province 10c and 20c are relatively common and readily available.
A quick search on Ebay shows completed NGC and PCGS MS62-63 of this type at about $70-130, and $200ish only at MS-64.
Both of your pieces are circulated, and even slabbed, I can't see them selling for more than $50 apiece with shipping.
Chinese silver dollars are hot. The 10 cent and 20 cent coins, not so much, partially because silver dollars have a natural "big coin" attraction to them, and also because the mintages and survival rate of the workhorse dime and double dime are vastly higher.