You mean the fixed width text? There aren't any pointers, not in the traditional sense. In order to expand this, you need to change the number of characters loaded and printed. Here's what prints the item names in the Item menu:
C3/80B9: A28B9E LDX #$9E8B (position onscreen, though a couple of people have mentioned this may be where in VRAM it is stored)
C3/80BC: 8E8121 STX $2181
C3/80BF: AD1242 LDA $4212
C3/80C2: 2940 AND #$40
C3/80C4: F0F9 BEQ $80BF
C3/80C6: 7B TDC
C3/80C7: B96918 LDA $1869,Y (Load inventory item Y)
C3/80CA: C9FF CMP #$FF (Is it the "empty" item?)
C3/80CC: F028 BEQ $80F6 (If so, skip to the next part)
C3/80CE: 8D1B21 STA $211B (Write the index out to be multiplied)
C3/80D1: 9C1B21 STZ $211B (It always does this...)
C3/80D4: A90D LDA #$0D (Load 13)
C3/80D6: 8D1C21 STA $211C (Write it out to be multiplied)
C3/80D9: 8D1C21 STA $211C (Write it out again, as required)
C3/80DC: AE3421 LDX $2134 (Load X with the result of index * 13)
C3/80DF: A00D00 LDY #$000D (Start the count of letters at 13)
C3/80E2: BF00B3D2 LDA $D2B300,X (Load letter X of item name)
C3/80E6: 8D8021 STA $2180
C3/80E9: E8 INX
C3/80EA: 88 DEY
C3/80EB: D0F5 BNE $80E2
C3/80ED: A9C1 LDA #$C1 (colon in the font)
C3/80EF: 8D8021 STA $2180
C3/80F2: 9C8021 STZ $2180
C3/80F5: 60 RTS
All you need to do is change the value at C3/80D5 and C3/80E0 to the number of characters you want to load instead. I believe all of the fixed width text is loaded in the same manner. All you need to do is have the starting offset of the text you want (SNES HiROM format, no header), then search the disassemblies for something loading it.
Keep in mind that expanding this even one character will completely throw off the existing names, and you'll need to be sure each one is now the new length. There are some fixed width dumping/insertion programs over at RHDN that might make this easier, but I've never used them. Alternatively, you could change these to load from a pointer table instead, which usually saves a ton of space. Maybe someone is feeling more ambitious and will teach you how to do that.